diff --git a/test/unit/app/controllers/transactions/tx-controller-test.js b/test/unit/app/controllers/transactions/tx-controller-test.js
index 6889f9bb2..74161e26c 100644
--- a/test/unit/app/controllers/transactions/tx-controller-test.js
+++ b/test/unit/app/controllers/transactions/tx-controller-test.js
@@ -413,7 +413,7 @@ describe('Transaction Controller', function () {
         gasPrice: '0xa',
       }
       txController.txStateManager._saveTxList([
-        { id: 1, status: 'submitted', metamaskNetworkId: currentNetworkId, txParams, history: [] },
+        { id: 1, status: 'submitted', metamaskNetworkId: currentNetworkId, txParams, history: [{}] },
       ])
 
       expectedTxParams = Object.assign({}, txParams, { gasPrice: '0xb'})
diff --git a/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/advanced-tab-content.component.js b/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/advanced-tab-content.component.js
index ac68b833c..ba738ff75 100644
--- a/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/advanced-tab-content.component.js
+++ b/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/advanced-tab-content.component.js
@@ -3,6 +3,7 @@ import PropTypes from 'prop-types'
 import classnames from 'classnames'
 import Loading from '../../../loading-screen'
 import GasPriceChart from '../../gas-price-chart'
+import debounce from 'lodash.debounce'
 
 export default class AdvancedTabContent extends Component {
   static contextTypes = {
@@ -22,7 +23,21 @@ export default class AdvancedTabContent extends Component {
     insufficientBalance: PropTypes.bool,
   }
 
-  gasInput (value, onChange, min, insufficientBalance, precision, showGWEI) {
+  constructor (props) {
+    super(props)
+
+    this.debouncedGasLimitReset = debounce((dVal) => {
+      if (dVal < 21000) {
+        props.updateCustomGasLimit(21000)
+      }
+    }, 1000, { trailing: true })
+    this.onChangeGasLimit = (val) => {
+      props.updateCustomGasLimit(val)
+      this.debouncedGasLimitReset(val)
+    }
+  }
+
+  gasInput (value, onChange, min, insufficientBalance, showGWEI) {
     return (
       <div className="advanced-tab__gas-edit-row__input-wrapper">
         <input
@@ -32,14 +47,13 @@ export default class AdvancedTabContent extends Component {
           type="number"
           value={value}
           min={min}
-          precision={precision}
           onChange={event => onChange(Number(event.target.value))}
         />
         <div className={classnames('advanced-tab__gas-edit-row__input-arrows', {
           'advanced-tab__gas-edit-row__input-arrows--error': insufficientBalance,
         })}>
-          <div className="advanced-tab__gas-edit-row__input-arrows__i-wrap"><i className="fa fa-sm fa-angle-up" onClick={() => onChange(value + 1)} /></div>
-          <div className="advanced-tab__gas-edit-row__input-arrows__i-wrap"><i className="fa fa-sm fa-angle-down" onClick={() => onChange(value - 1)} /></div>
+          <div className="advanced-tab__gas-edit-row__input-arrows__i-wrap" onClick={() => onChange(value + 1)}><i className="fa fa-sm fa-angle-up" /></div>
+          <div className="advanced-tab__gas-edit-row__input-arrows__i-wrap" onClick={() => onChange(value - 1)}><i className="fa fa-sm fa-angle-down" /></div>
         </div>
         {insufficientBalance && <div className="advanced-tab__gas-edit-row__insufficient-balance">
           Insufficient Balance
@@ -84,8 +98,8 @@ export default class AdvancedTabContent extends Component {
   renderGasEditRows (customGasPrice, updateCustomGasPrice, customGasLimit, updateCustomGasLimit, insufficientBalance) {
     return (
       <div className="advanced-tab__gas-edit-rows">
-        { this.renderGasEditRow('gasPrice', customGasPrice, updateCustomGasPrice, customGasPrice, insufficientBalance, 9, true) }
-        { this.renderGasEditRow('gasLimit', customGasLimit, updateCustomGasLimit, customGasLimit, insufficientBalance, 0) }
+        { this.renderGasEditRow('gasPrice', customGasPrice, updateCustomGasPrice, customGasPrice, insufficientBalance, true) }
+        { this.renderGasEditRow('gasLimit', customGasLimit, this.onChangeGasLimit, customGasLimit, insufficientBalance) }
       </div>
     )
   }
diff --git a/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/index.scss b/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/index.scss
index b62919c0a..88c69faf4 100644
--- a/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/index.scss
+++ b/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/index.scss
@@ -148,6 +148,7 @@
         height: 100%;
         display: flex;
         justify-content: center;
+        cursor: pointer;
       }
 
       &__i-wrap:hover {
diff --git a/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/tests/advanced-tab-content-component.test.js b/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/tests/advanced-tab-content-component.test.js
index f321ca696..d6920454d 100644
--- a/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/tests/advanced-tab-content-component.test.js
+++ b/ui/app/components/gas-customization/gas-modal-page-container/advanced-tab-content/tests/advanced-tab-content-component.test.js
@@ -155,8 +155,11 @@ describe('AdvancedTabContent Component', function () {
 
   describe('renderGasEditRows()', () => {
     let gasEditRows
+    let tempOnChangeGasLimit
 
     beforeEach(() => {
+      tempOnChangeGasLimit = wrapper.instance().onChangeGasLimit
+      wrapper.instance().onChangeGasLimit = () => 'mockOnChangeGasLimit'
       AdvancedTabContent.prototype.renderGasEditRow.resetHistory()
       gasEditRows = shallow(wrapper.instance().renderGasEditRows(
         'mockGasPrice',
@@ -167,6 +170,10 @@ describe('AdvancedTabContent Component', function () {
       ))
     })
 
+    afterEach(() => {
+      wrapper.instance().onChangeGasLimit = tempOnChangeGasLimit
+    })
+
     it('should render the gas-edit-rows root node', () => {
       assert(gasEditRows.hasClass('advanced-tab__gas-edit-rows'))
     })
@@ -182,10 +189,10 @@ describe('AdvancedTabContent Component', function () {
       const renderGasEditRowSpyArgs = AdvancedTabContent.prototype.renderGasEditRow.args
       assert.equal(renderGasEditRowSpyArgs.length, 2)
       assert.deepEqual(renderGasEditRowSpyArgs[0].map(String), [
-        'gasPrice', 'mockGasPrice', () => 'mockUpdateCustomGasPriceReturn', 'mockGasPrice', false, 9, true,
+        'gasPrice', 'mockGasPrice', () => 'mockUpdateCustomGasPriceReturn', 'mockGasPrice', false, true,
       ].map(String))
       assert.deepEqual(renderGasEditRowSpyArgs[1].map(String), [
-        'gasLimit', 'mockGasLimit', () => 'mockUpdateCustomGasLimitReturn', 'mockGasLimit', false, 0,
+        'gasLimit', 'mockGasLimit', () => 'mockOnChangeGasLimit', 'mockGasLimit', false,
       ].map(String))
     })
   })
@@ -234,7 +241,6 @@ describe('AdvancedTabContent Component', function () {
       const inputProps = gasInput.find('input').props()
       assert.equal(inputProps.min, 0)
       assert.equal(inputProps.value, 321)
-      assert.equal(inputProps.precision, 8)
     })
 
     it('should call the passed onChange method with the value of the input onChange event', () => {
@@ -257,9 +263,9 @@ describe('AdvancedTabContent Component', function () {
         8,
         false
       ))
-      const upArrow = gasInput.find('.fa-angle-up')
+      const upArrow = gasInput.find('.advanced-tab__gas-edit-row__input-arrows__i-wrap').at(0)
       assert.equal(upArrow.props().onClick(), 329)
-      const downArrow = gasInput.find('.fa-angle-down')
+      const downArrow = gasInput.find('.advanced-tab__gas-edit-row__input-arrows__i-wrap').at(1)
       assert.equal(downArrow.props().onClick(), 327)
     })
   })
diff --git a/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.component.js b/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.component.js
index 5d8f92a59..be91bef0f 100644
--- a/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.component.js
+++ b/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.component.js
@@ -89,7 +89,7 @@ export default class GasModalPageContainer extends Component {
 
   renderInfoRows (newTotalFiat, newTotalEth, sendAmount, transactionFee) {
     return (
-      <div>
+      <div className="gas-modal-content__info-row-wrapper">
         <div className="gas-modal-content__info-row">
           <div className="gas-modal-content__info-row__send-info">
             <span className="gas-modal-content__info-row__send-info__label">{this.context.t('sendAmount')}</span>
@@ -167,7 +167,6 @@ export default class GasModalPageContainer extends Component {
           onClose={() => cancelAndClose()}
           onSubmit={() => {
             onSubmit(customModalGasLimitInHex, customModalGasPriceInHex)
-            cancelAndClose()
           }}
           submitText={this.context.t('save')}
           headerCloseText={'Close'}
diff --git a/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.container.js b/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.container.js
index 42b96a729..c619a0988 100644
--- a/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.container.js
+++ b/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.container.js
@@ -142,6 +142,7 @@ const mapDispatchToProps = dispatch => {
       dispatch(resetCustomData())
       dispatch(hideModal())
     },
+    hideModal: () => dispatch(hideModal()),
     updateCustomGasPrice,
     convertThenUpdateCustomGasPrice: newPrice => updateCustomGasPrice(decGWEIToHexWEI(newPrice)),
     convertThenUpdateCustomGasLimit: newLimit => dispatch(setCustomGasLimit(addHexPrefix(newLimit.toString(16)))),
@@ -150,6 +151,8 @@ const mapDispatchToProps = dispatch => {
       dispatch(setGasPrice(newPrice))
     },
     updateConfirmTxGasAndCalculate: (gasLimit, gasPrice) => {
+      updateCustomGasPrice(gasPrice)
+      dispatch(setCustomGasLimit(addHexPrefix(gasLimit.toString(16))))
       return dispatch(updateGasAndCalculate({ gasLimit, gasPrice }))
     },
     createSpeedUpTransaction: (txId, gasPrice) => {
@@ -172,6 +175,8 @@ const mergeProps = (stateProps, dispatchProps, ownProps) => {
     updateConfirmTxGasAndCalculate: dispatchUpdateConfirmTxGasAndCalculate,
     createSpeedUpTransaction: dispatchCreateSpeedUpTransaction,
     hideSidebar: dispatchHideSidebar,
+    cancelAndClose: dispatchCancelAndClose,
+    hideModal: dispatchHideModal,
     ...otherDispatchProps
   } = dispatchProps
 
@@ -182,18 +187,27 @@ const mergeProps = (stateProps, dispatchProps, ownProps) => {
     onSubmit: (gasLimit, gasPrice) => {
       if (isConfirm) {
         dispatchUpdateConfirmTxGasAndCalculate(gasLimit, gasPrice)
+        dispatchHideModal()
       } else if (isSpeedUp) {
         dispatchCreateSpeedUpTransaction(txId, gasPrice)
         dispatchHideSidebar()
+        dispatchCancelAndClose()
       } else {
         dispatchSetGasData(gasLimit, gasPrice)
         dispatchHideGasButtonGroup()
+        dispatchCancelAndClose()
       }
     },
     gasPriceButtonGroupProps: {
       ...gasPriceButtonGroupProps,
       handleGasPriceSelection: dispatchUpdateCustomGasPrice,
     },
+    cancelAndClose: () => {
+      dispatchCancelAndClose()
+      if (isSpeedUp) {
+        dispatchHideSidebar()
+      }
+    },
   }
 }
 
@@ -241,20 +255,29 @@ function addHexWEIsToRenderableFiat (aHexWEI, bHexWEI, convertedCurrency, conver
 }
 
 function getRenderableTimeEstimate (currentGasPrice, gasPrices, estimatedTimes) {
+  const minGasPrice = gasPrices[0]
+  const maxGasPrice = gasPrices[gasPrices.length - 1]
+  let priceForEstimation = currentGasPrice
+  if (currentGasPrice < minGasPrice) {
+    priceForEstimation = minGasPrice
+  } else if (currentGasPrice > maxGasPrice) {
+    priceForEstimation = maxGasPrice
+  }
+
   const {
     closestLowerValueIndex,
     closestHigherValueIndex,
     closestHigherValue,
     closestLowerValue,
-  } = getAdjacentGasPrices({ gasPrices, priceToPosition: currentGasPrice })
+  } = getAdjacentGasPrices({ gasPrices, priceToPosition: priceForEstimation })
 
   const newTimeEstimate = extrapolateY({
     higherY: estimatedTimes[closestHigherValueIndex],
     lowerY: estimatedTimes[closestLowerValueIndex],
     higherX: closestHigherValue,
     lowerX: closestLowerValue,
-    xForExtrapolation: currentGasPrice,
+    xForExtrapolation: priceForEstimation,
   })
 
-  return formatTimeEstimate(newTimeEstimate)
+  return formatTimeEstimate(newTimeEstimate, currentGasPrice > maxGasPrice, currentGasPrice < minGasPrice)
 }
diff --git a/ui/app/components/gas-customization/gas-modal-page-container/index.scss b/ui/app/components/gas-customization/gas-modal-page-container/index.scss
index 2532c1fc2..6c76f1bdd 100644
--- a/ui/app/components/gas-customization/gas-modal-page-container/index.scss
+++ b/ui/app/components/gas-customization/gas-modal-page-container/index.scss
@@ -44,6 +44,7 @@
       display: flex;
       justify-content: center;
       align-items: flex-start;
+      margin-right: 0;
     }
 
     &__subtitle {
diff --git a/ui/app/components/gas-customization/gas-modal-page-container/tests/gas-modal-page-container-container.test.js b/ui/app/components/gas-customization/gas-modal-page-container/tests/gas-modal-page-container-container.test.js
index 82c6dcd69..512832866 100644
--- a/ui/app/components/gas-customization/gas-modal-page-container/tests/gas-modal-page-container-container.test.js
+++ b/ui/app/components/gas-customization/gas-modal-page-container/tests/gas-modal-page-container-container.test.js
@@ -82,10 +82,10 @@ describe('gas-modal-page-container container', () => {
           },
           gasEstimatesLoading: false,
           priceAndTimeEstimates: [
-            { gasprice: 3, expectedTime: '31' },
-            { gasprice: 4, expectedTime: '62' },
-            { gasprice: 5, expectedTime: '93' },
-            { gasprice: 6, expectedTime: '124' },
+            { gasprice: 3, expectedTime: 31 },
+            { gasprice: 4, expectedTime: 62 },
+            { gasprice: 5, expectedTime: 93 },
+            { gasprice: 6, expectedTime: 124 },
           ],
         },
         confirmTransaction: {
@@ -235,7 +235,7 @@ describe('gas-modal-page-container container', () => {
     describe('updateConfirmTxGasAndCalculate()', () => {
       it('should dispatch a updateGasAndCalculate action with the correct props', () => {
         mapDispatchToPropsObject.updateConfirmTxGasAndCalculate('ffff', 'aaaa')
-        assert(dispatchSpy.calledOnce)
+        assert.equal(dispatchSpy.callCount, 3)
         assert(confirmTransactionActionSpies.updateGasAndCalculate.calledOnce)
         assert.deepEqual(confirmTransactionActionSpies.updateGasAndCalculate.getCall(0).args[0], { gasLimit: 'ffff', gasPrice: 'aaaa' })
       })
@@ -265,6 +265,8 @@ describe('gas-modal-page-container container', () => {
           someOtherDispatchProp: sinon.spy(),
           createSpeedUpTransaction: sinon.spy(),
           hideSidebar: sinon.spy(),
+          hideModal: sinon.spy(),
+          cancelAndClose: sinon.spy(),
         }
         ownProps = { someOwnProp: 123 }
       })
@@ -277,6 +279,7 @@ describe('gas-modal-page-container container', () => {
         dispatchProps.someOtherDispatchProp.resetHistory()
         dispatchProps.createSpeedUpTransaction.resetHistory()
         dispatchProps.hideSidebar.resetHistory()
+        dispatchProps.hideModal.resetHistory()
       })
     it('should return the expected props when isConfirm is true', () => {
       const result = mergeProps(stateProps, dispatchProps, ownProps)
@@ -290,12 +293,14 @@ describe('gas-modal-page-container container', () => {
       assert.equal(dispatchProps.updateConfirmTxGasAndCalculate.callCount, 0)
       assert.equal(dispatchProps.setGasData.callCount, 0)
       assert.equal(dispatchProps.hideGasButtonGroup.callCount, 0)
+      assert.equal(dispatchProps.hideModal.callCount, 0)
 
       result.onSubmit()
 
       assert.equal(dispatchProps.updateConfirmTxGasAndCalculate.callCount, 1)
       assert.equal(dispatchProps.setGasData.callCount, 0)
       assert.equal(dispatchProps.hideGasButtonGroup.callCount, 0)
+      assert.equal(dispatchProps.hideModal.callCount, 1)
 
       assert.equal(dispatchProps.updateCustomGasPrice.callCount, 0)
       result.gasPriceButtonGroupProps.handleGasPriceSelection()
@@ -318,6 +323,7 @@ describe('gas-modal-page-container container', () => {
       assert.equal(dispatchProps.updateConfirmTxGasAndCalculate.callCount, 0)
       assert.equal(dispatchProps.setGasData.callCount, 0)
       assert.equal(dispatchProps.hideGasButtonGroup.callCount, 0)
+      assert.equal(dispatchProps.cancelAndClose.callCount, 0)
 
       result.onSubmit('mockNewLimit', 'mockNewPrice')
 
@@ -325,6 +331,7 @@ describe('gas-modal-page-container container', () => {
       assert.equal(dispatchProps.setGasData.callCount, 1)
       assert.deepEqual(dispatchProps.setGasData.getCall(0).args, ['mockNewLimit', 'mockNewPrice'])
       assert.equal(dispatchProps.hideGasButtonGroup.callCount, 1)
+      assert.equal(dispatchProps.cancelAndClose.callCount, 1)
 
       assert.equal(dispatchProps.updateCustomGasPrice.callCount, 0)
       result.gasPriceButtonGroupProps.handleGasPriceSelection()
@@ -343,6 +350,7 @@ describe('gas-modal-page-container container', () => {
       assert.equal(dispatchProps.updateConfirmTxGasAndCalculate.callCount, 0)
       assert.equal(dispatchProps.setGasData.callCount, 0)
       assert.equal(dispatchProps.hideGasButtonGroup.callCount, 0)
+      assert.equal(dispatchProps.cancelAndClose.callCount, 1)
 
       assert.equal(dispatchProps.createSpeedUpTransaction.callCount, 1)
       assert.equal(dispatchProps.hideSidebar.callCount, 1)
diff --git a/ui/app/components/gas-customization/gas-price-button-group/index.scss b/ui/app/components/gas-customization/gas-price-button-group/index.scss
index 6e9d01c6e..0d1450594 100644
--- a/ui/app/components/gas-customization/gas-price-button-group/index.scss
+++ b/ui/app/components/gas-customization/gas-price-button-group/index.scss
@@ -137,7 +137,7 @@
 .gas-price-button-group--alt {
   display: flex;
   justify-content: stretch;
-  max-width: 342px;
+  width: 95%;
 
   &__button-fiat-price {
     font-size: 13px;
diff --git a/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.component.js b/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.component.js
index 3f382e5b2..d4c67bbde 100644
--- a/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.component.js
+++ b/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.component.js
@@ -19,7 +19,7 @@ export default class GasPriceChart extends Component {
     gasPrices: PropTypes.array,
     estimatedTimes: PropTypes.array,
     gasPricesMax: PropTypes.number,
-    estimatedTimesMax: PropTypes.string,
+    estimatedTimesMax: PropTypes.number,
     currentPrice: PropTypes.number,
     updateCustomGasPrice: PropTypes.func,
   }
diff --git a/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.utils.js b/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.utils.js
index 0b9dfbd11..f19dafcc1 100644
--- a/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.utils.js
+++ b/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.utils.js
@@ -1,5 +1,11 @@
 import * as d3 from 'd3'
 import c3 from 'c3'
+import BigNumber from 'bignumber.js'
+
+const newBigSigDig = n => (new BigNumber(n.toPrecision(15)))
+const createOp = (a, b, op) => (newBigSigDig(a))[op](newBigSigDig(b))
+const bigNumMinus = (a = 0, b = 0) => createOp(a, b, 'minus')
+const bigNumDiv = (a = 0, b = 1) => createOp(a, b, 'div')
 
 export function handleMouseMove ({ xMousePos, chartXStart, chartWidth, gasPrices, estimatedTimes, chart }) {
   const { currentPosValue, newTimeEstimate } = getNewXandTimeEstimate({
@@ -24,7 +30,8 @@ export function handleMouseMove ({ xMousePos, chartXStart, chartWidth, gasPrices
 }
 
 export function getCoordinateData (selector) {
-   return d3.select(selector).node().getBoundingClientRect()
+  const node = d3.select(selector).node()
+  return node ? node.getBoundingClientRect() : {}
 }
 
 export function generateDataUIObj (x, index, value) {
@@ -70,19 +77,22 @@ export function getAdjacentGasPrices ({ gasPrices, priceToPosition }) {
   }
 }
 
-export function extrapolateY ({ higherY, lowerY, higherX, lowerX, xForExtrapolation }) {
-  const slope = (higherY - lowerY) / (higherX - lowerX)
-  const newTimeEstimate = -1 * (slope * (higherX - xForExtrapolation) - higherY)
+export function extrapolateY ({ higherY = 0, lowerY = 0, higherX = 0, lowerX = 0, xForExtrapolation = 0 }) {
+  const slope = bigNumMinus(higherY, lowerY).div(bigNumMinus(higherX, lowerX))
+  const newTimeEstimate = slope.times(bigNumMinus(higherX, xForExtrapolation)).minus(newBigSigDig(higherY)).negated()
 
-  return newTimeEstimate
+  return newTimeEstimate.toNumber()
 }
 
 
 export function getNewXandTimeEstimate ({ xMousePos, chartXStart, chartWidth, gasPrices, estimatedTimes }) {
-  const chartMouseXPos = xMousePos - chartXStart
-  const posPercentile = chartMouseXPos / chartWidth
+  const chartMouseXPos = bigNumMinus(xMousePos, chartXStart)
+  const posPercentile = bigNumDiv(chartMouseXPos, chartWidth)
 
-  const currentPosValue = (gasPrices[gasPrices.length - 1] - gasPrices[0]) * posPercentile + gasPrices[0]
+  const currentPosValue = (bigNumMinus(gasPrices[gasPrices.length - 1], gasPrices[0]))
+    .times(newBigSigDig(posPercentile))
+    .plus(newBigSigDig(gasPrices[0]))
+    .toNumber()
 
   const {
     closestLowerValueIndex,
@@ -162,20 +172,28 @@ export function setSelectedCircle ({
   closestHigherValue,
 }) {
   const numberOfValues = chart.internal.data.xs.data1.length
+
   const { x: lowerX, y: lowerY } = getCoordinateData(`.c3-circle-${closestLowerValueIndex}`)
   let { x: higherX, y: higherY } = getCoordinateData(`.c3-circle-${closestHigherValueIndex}`)
+  let count = closestHigherValueIndex + 1
 
-  if (lowerX === higherX) {
-    const { x: higherXAdjusted, y: higherYAdjusted } = getCoordinateData(`.c3-circle-${closestHigherValueIndex + 1}`)
-    higherY = higherYAdjusted
-    higherX = higherXAdjusted
+  if (lowerX && higherX) {
+    while (lowerX === higherX) {
+      higherX = getCoordinateData(`.c3-circle-${count}`).x
+      higherY = getCoordinateData(`.c3-circle-${count}`).y
+      count++
+    }
   }
 
-  const currentX = lowerX + (higherX - lowerX) * (newPrice - closestLowerValue) / (closestHigherValue - closestLowerValue)
+  const currentX = bigNumMinus(higherX, lowerX)
+    .times(bigNumMinus(newPrice, closestLowerValue))
+    .div(bigNumMinus(closestHigherValue, closestLowerValue))
+    .plus(newBigSigDig(lowerX))
+
   const newTimeEstimate = extrapolateY({ higherY, lowerY, higherX, lowerX, xForExtrapolation: currentX })
 
   chart.internal.selectPoint(
-    generateDataUIObj(currentX, numberOfValues, newTimeEstimate),
+    generateDataUIObj(currentX.toNumber(), numberOfValues, newTimeEstimate),
     numberOfValues
   )
 }
@@ -282,8 +300,8 @@ export function generateChart (gasPrices, estimatedTimes, gasPricesMax, estimate
         .style('margin-top', flipTooltip ? '-16px' : '4px')
 
         return {
-          top: circleY - chartYStart - 19 + (flipTooltip ? circleWidth + 38 : 0),
-          left: circleX - chartXStart + circleWidth - (gasPricesMaxPadded / 50),
+          top: bigNumMinus(circleY, chartYStart).minus(19).plus(flipTooltip ? circleWidth + 38 : 0).toNumber(),
+          left: bigNumMinus(circleX, chartXStart).plus(newBigSigDig(circleWidth)).minus(bigNumDiv(gasPricesMaxPadded, 50)).toNumber(),
         }
       },
       show: true,
@@ -298,8 +316,8 @@ export function generateChart (gasPrices, estimatedTimes, gasPricesMax, estimate
     appendOrUpdateCircle.bind(this)({
       data,
       itemIndex,
-      cx: () => data.x - chartXStart + 11,
-      cy: () => data.value - chartYStart + 10,
+      cx: () => bigNumMinus(data.x, chartXStart).plus(11).toNumber(),
+      cy: () => bigNumMinus(data.value, chartYStart).plus(10).toNumber(),
       cssId: 'set-circle',
       appendOnly: true,
     })
diff --git a/ui/app/components/modals/modal.js b/ui/app/components/modals/modal.js
index 7ed0b6944..0a603db4e 100644
--- a/ui/app/components/modals/modal.js
+++ b/ui/app/components/modals/modal.js
@@ -399,7 +399,7 @@ function mapDispatchToProps (dispatch) {
   return {
     hideModal: (customOnHideOpts) => {
       dispatch(actions.hideModal())
-      if (customOnHideOpts.action) {
+      if (customOnHideOpts && customOnHideOpts.action) {
         dispatch(customOnHideOpts.action(...customOnHideOpts.args))
       }
     },
diff --git a/ui/app/components/page-container/page-container-footer/page-container-footer.component.js b/ui/app/components/page-container/page-container-footer/page-container-footer.component.js
index 5725c22ac..85b16cefe 100644
--- a/ui/app/components/page-container/page-container-footer/page-container-footer.component.js
+++ b/ui/app/components/page-container/page-container-footer/page-container-footer.component.js
@@ -12,7 +12,7 @@ export default class PageContainerFooter extends Component {
     submitText: PropTypes.string,
     disabled: PropTypes.bool,
     submitButtonType: PropTypes.string,
-    hideCancel: PropTypes.func,
+    hideCancel: PropTypes.bool,
   }
 
   static contextTypes = {
diff --git a/ui/app/components/sidebars/sidebar-content.scss b/ui/app/components/sidebars/sidebar-content.scss
index 7d1f719dc..ca6b0a458 100644
--- a/ui/app/components/sidebars/sidebar-content.scss
+++ b/ui/app/components/sidebars/sidebar-content.scss
@@ -1,6 +1,11 @@
 .sidebar-left {
+  display: flex;
+
   .gas-modal-page-container {
+    display: flex;
+
     .page-container {
+      flex: 1;
       max-width: 100%;
 
       &__content {
@@ -12,6 +17,10 @@
         max-width: 344px;
         min-height: auto;
       }
+
+      @media screen and (min-width: $break-small) {
+        max-height: none;
+      }
     }
 
     .gas-price-chart {
@@ -34,9 +43,10 @@
     }
 
     .basic-tab-content {
-      height: 318px;
+      height: auto;
       margin-bottom: 0px;
       border-bottom: 1px solid #d2d8dd;
+      flex: 1 1 70%;
 
       @media screen and (max-width: $break-small) {
         padding-left: 14px;
@@ -55,6 +65,10 @@
     }
 
     .advanced-tab {
+      @media screen and (min-width: $break-small) {
+        flex: 1 1 70%;
+      }
+
       &__fee-chart {
         height: 320px;
 
@@ -72,14 +86,26 @@
       }
     }
 
+    .gas-modal-content {
+      display: flex;
+      flex-direction: column;
+      width: 100%;
 
-    .gas-modal-content__info-row {
-      height: 170px;
-
-      @media screen and (max-width: $break-small) {
-        height: initial;
+      &__info-row-wrapper {
         display: flex;
-        justify-content: center;
+        @media screen and (min-width: $break-small) {
+          flex: 1 1 30%;
+        }
+      }
+
+      &__info-row {
+        height: 170px;
+
+        @media screen and (max-width: $break-small) {
+          height: initial;
+          display: flex;
+          justify-content: center;
+        }
       }
     }
   }
diff --git a/ui/app/ducks/gas.duck.js b/ui/app/ducks/gas.duck.js
index 20a125dbb..8db24cc83 100644
--- a/ui/app/ducks/gas.duck.js
+++ b/ui/app/ducks/gas.duck.js
@@ -220,18 +220,25 @@ export function fetchBasicGasAndTimeEstimates () {
       )
         .then(r => r.json())
         .then(({
-          average,
+          average: averageTimes10,
           avgWait,
           block_time: blockTime,
           blockNum,
-          fast,
-          fastest,
+          fast: fastTimes10,
+          fastest: fastestTimes10,
           fastestWait,
           fastWait,
-          safeLow,
+          safeLow: safeLowTimes10,
           safeLowWait,
           speed,
         }) => {
+          const [average, fast, fastest, safeLow] = [
+            averageTimes10,
+            fastTimes10,
+            fastestTimes10,
+            safeLowTimes10,
+          ].map(price => (new BigNumber(price)).div(10).toNumber())
+
           const basicEstimates = {
             average,
             avgWait,
diff --git a/ui/app/ducks/tests/gas-duck.test.js b/ui/app/ducks/tests/gas-duck.test.js
index 4783db30c..bf374c7ec 100644
--- a/ui/app/ducks/tests/gas-duck.test.js
+++ b/ui/app/ducks/tests/gas-duck.test.js
@@ -32,15 +32,15 @@ describe('Gas Duck', () => {
   let tempFetch
   let tempDateNow
   const mockEthGasApiResponse = {
-    average: 'mockAverage',
+    average: 20,
     avgWait: 'mockAvgWait',
     block_time: 'mockBlock_time',
     blockNum: 'mockBlockNum',
-    fast: 'mockFast',
-    fastest: 'mockFastest',
+    fast: 30,
+    fastest: 40,
     fastestWait: 'mockFastestWait',
     fastWait: 'mockFastWait',
-    safeLow: 'mockSafeLow',
+    safeLow: 10,
     safeLowWait: 'mockSafeLowWait',
     speed: 'mockSpeed',
   }
@@ -338,15 +338,15 @@ describe('Gas Duck', () => {
         [{
           type: SET_BASIC_GAS_ESTIMATE_DATA,
           value: {
-            average: 'mockAverage',
+            average: 2,
             avgWait: 'mockAvgWait',
             blockTime: 'mockBlock_time',
             blockNum: 'mockBlockNum',
-            fast: 'mockFast',
-            fastest: 'mockFastest',
+            fast: 3,
+            fastest: 4,
             fastestWait: 'mockFastestWait',
             fastWait: 'mockFastWait',
-            safeLow: 'mockSafeLow',
+            safeLow: 1,
             safeLowWait: 'mockSafeLowWait',
             speed: 'mockSpeed',
           },
diff --git a/ui/app/selectors/custom-gas.js b/ui/app/selectors/custom-gas.js
index ec234500d..59f240f9c 100644
--- a/ui/app/selectors/custom-gas.js
+++ b/ui/app/selectors/custom-gas.js
@@ -85,9 +85,9 @@ function getAveragePriceEstimateInHexWEI (state) {
   return getGasPriceInHexWei(averagePriceEstimate || '0x0')
 }
 
-function getFastPriceEstimateInHexWEI (state, convertFromDecGWEI) {
+function getFastPriceEstimateInHexWEI (state) {
   const fastPriceEstimate = state.gas.basicEstimates.fast
-  return getGasPriceInHexWei(fastPriceEstimate || '0x0', convertFromDecGWEI)
+  return getGasPriceInHexWei(fastPriceEstimate || '0x0')
 }
 
 function getDefaultActiveButtonIndex (gasButtonInfo, customGasPriceInHex, gasPrice) {
@@ -100,15 +100,6 @@ function getBasicGasEstimateBlockTime (state) {
   return state.gas.basicEstimates.blockTime
 }
 
-function apiEstimateModifiedToGWEI (estimate) {
-  return multiplyCurrencies(estimate, 0.10, {
-    toNumericBase: 'hex',
-    multiplicandBase: 10,
-    multiplierBase: 10,
-    numberOfDecimals: 9,
-  })
-}
-
 function basicPriceEstimateToETHTotal (estimate, gasLimit, numberOfDecimals = 9) {
   return conversionUtil(calcGasTotal(gasLimit, estimate), {
     fromNumericBase: 'hex',
@@ -118,26 +109,18 @@ function basicPriceEstimateToETHTotal (estimate, gasLimit, numberOfDecimals = 9)
   })
 }
 
-function getRenderableEthFee (estimate, gasLimit, numberOfDecimals = 9, convertFromDecGWEI) {
-  const initialConversion = convertFromDecGWEI
-    ? x => conversionUtil(x, { fromNumericBase: 'dec', toNumericBase: 'hex' })
-    : apiEstimateModifiedToGWEI
-
+function getRenderableEthFee (estimate, gasLimit, numberOfDecimals = 9) {
   return pipe(
-    initialConversion,
+    x => conversionUtil(x, { fromNumericBase: 'dec', toNumericBase: 'hex' }),
     partialRight(basicPriceEstimateToETHTotal, [gasLimit, numberOfDecimals]),
     formatETHFee
   )(estimate, gasLimit)
 }
 
 
-function getRenderableConvertedCurrencyFee (estimate, gasLimit, convertedCurrency, conversionRate, convertFromDecGWEI) {
-  const initialConversion = convertFromDecGWEI
-    ? x => conversionUtil(x, { fromNumericBase: 'dec', toNumericBase: 'hex' })
-    : apiEstimateModifiedToGWEI
-
+function getRenderableConvertedCurrencyFee (estimate, gasLimit, convertedCurrency, conversionRate) {
   return pipe(
-    initialConversion,
+    x => conversionUtil(x, { fromNumericBase: 'dec', toNumericBase: 'hex' }),
     partialRight(basicPriceEstimateToETHTotal, [gasLimit]),
     partialRight(ethTotalToConvertedCurrency, [convertedCurrency, conversionRate]),
     partialRight(formatCurrency, [convertedCurrency])
@@ -153,14 +136,26 @@ function getTimeEstimateInSeconds (blockWaitEstimate) {
   })
 }
 
-function formatTimeEstimate (totalSeconds) {
+function formatTimeEstimate (totalSeconds, greaterThanMax, lessThanMin) {
   const minutes = Math.floor(totalSeconds / 60)
   const seconds = Math.floor(totalSeconds % 60)
+
+  if (!minutes && !seconds) {
+    return '...'
+  }
+
+  let symbol = '~'
+  if (greaterThanMax) {
+    symbol = '< '
+  } else if (lessThanMin) {
+    symbol = '> '
+  }
+
   const formattedMin = `${minutes ? minutes + ' min' : ''}`
   const formattedSec = `${seconds ? seconds + ' sec' : ''}`
   const formattedCombined = formattedMin && formattedSec
-    ? `~${formattedMin} ${formattedSec}`
-    : '~' + [formattedMin, formattedSec].find(t => t)
+    ? `${symbol}${formattedMin} ${formattedSec}`
+    : symbol + [formattedMin, formattedSec].find(t => t)
 
   return formattedCombined
 }
@@ -182,13 +177,9 @@ function priceEstimateToWei (priceEstimate) {
   })
 }
 
-function getGasPriceInHexWei (price, convertFromDecGWEI) {
-  const initialConversion = convertFromDecGWEI
-    ? x => conversionUtil(x, { fromNumericBase: 'dec', toNumericBase: 'hex' })
-    : apiEstimateModifiedToGWEI
-
+function getGasPriceInHexWei (price) {
   return pipe(
-    initialConversion,
+    x => conversionUtil(x, { fromNumericBase: 'dec', toNumericBase: 'hex' }),
     priceEstimateToWei,
     addHexPrefix
   )(price)
@@ -259,19 +250,19 @@ function getRenderableEstimateDataForSmallButtonsFromGWEI (state) {
   return [
     {
       labelKey: 'fastest',
-      feeInSecondaryCurrency: getRenderableConvertedCurrencyFee(fastest, gasLimit, currentCurrency, conversionRate, true),
+      feeInSecondaryCurrency: getRenderableConvertedCurrencyFee(fastest, gasLimit, currentCurrency, conversionRate),
       feeInPrimaryCurrency: getRenderableEthFee(fastest, gasLimit, NUMBER_OF_DECIMALS_SM_BTNS, true),
       priceInHexWei: getGasPriceInHexWei(fastest, true),
     },
     {
       labelKey: 'fast',
-      feeInSecondaryCurrency: getRenderableConvertedCurrencyFee(fast, gasLimit, currentCurrency, conversionRate, true),
+      feeInSecondaryCurrency: getRenderableConvertedCurrencyFee(fast, gasLimit, currentCurrency, conversionRate),
       feeInPrimaryCurrency: getRenderableEthFee(fast, gasLimit, NUMBER_OF_DECIMALS_SM_BTNS, true),
       priceInHexWei: getGasPriceInHexWei(fast, true),
     },
     {
       labelKey: 'slow',
-      feeInSecondaryCurrency: getRenderableConvertedCurrencyFee(safeLow, gasLimit, currentCurrency, conversionRate, true),
+      feeInSecondaryCurrency: getRenderableConvertedCurrencyFee(safeLow, gasLimit, currentCurrency, conversionRate),
       feeInPrimaryCurrency: getRenderableEthFee(safeLow, gasLimit, NUMBER_OF_DECIMALS_SM_BTNS, true),
       priceInHexWei: getGasPriceInHexWei(safeLow, true),
     },
diff --git a/ui/app/selectors/tests/custom-gas.test.js b/ui/app/selectors/tests/custom-gas.test.js
index 037b1e86e..ebc300160 100644
--- a/ui/app/selectors/tests/custom-gas.test.js
+++ b/ui/app/selectors/tests/custom-gas.test.js
@@ -109,11 +109,11 @@ describe('custom-gas selectors', () => {
           gas: {
             basicEstimates: {
               blockTime: 14.16326530612245,
-              safeLow: 25,
+              safeLow: 2.5,
               safeLowWait: 6.6,
-              fast: 50,
+              fast: 5,
               fastWait: 3.3,
-              fastest: 100,
+              fastest: 10,
               fastestWait: 0.5,
             },
           },
@@ -154,11 +154,11 @@ describe('custom-gas selectors', () => {
           gas: {
             basicEstimates: {
               blockTime: 14.16326530612245,
-              safeLow: 50,
+              safeLow: 5,
               safeLowWait: 13.2,
-              fast: 100,
+              fast: 10,
               fastWait: 6.6,
-              fastest: 200,
+              fastest: 20,
               fastestWait: 1.0,
             },
           },