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Fuel Mileage Calculator to Calculate and Compare Car Gas Mileage

Calculator Preferences
Fuel Mileage Calculator

This calculator will calculate your vehicle's MPG and its associated daily, monthly, annual, and lifetime gas expenses, plus allows you to compare your car's gas mileage expenses against higher MPG ratings to see how much you will save if you switch to a car that gets better fuel economy. The Learn tab includes:

  • Why the price of gas is NOT to blame for high fuel costs.
  • How to calculate miles per gallon manually (MPG formula).
Learn More

Selected Data Record:

A Data Record is a set of calculator entries that are stored in your web browser's Local Storage. If a Data Record is currently selected in the "Data" tab, this line will list the name you gave to that data record. If no data record is selected, or you have no entries stored for this calculator, the line will display "None".

DataData recordData recordSelected data record: None
Beg odom:Begin odometer:Beginning odometer reading:Beginning odometer reading:

Beginning odometer reading:

If you have not done so already, record the odometer reading the next time you fill up the gas tank on your car. This is the beginning odometer reading you will need to enter on this line.

End odom:Ending odometer:Ending odometer reading:Ending odometer reading:

Ending odometer reading:

Once you have a beginning odometer reading, the next step is to record the odometer reading when you go to refill your tank. This is the ending odometer reading you will need to enter on this line.

# gallons:# of gallons:Number of gallons this fill:Number of gallons pumped this fill:

Number of gallons pumped this fill:

Enter the number of gallons of gas it took to refill the gas tank on your car. Be sure to include the decimal portion of the gallons meter on the gas pump.

Gas price:Gallon gas price:Price per gallon of gas:Price of one gallon of gasoline:

Price of one gallon of gasoline:

Enter the current price of one gallon of gasoline (or diesel fuel), but without the dollar sign. The calculator will use this figure to forecast your periodic fuel expenses.

Average miles:Average miles:Average miles:Average miles:

Average number of miles driven per period:

Select the mileage time period for which you know the average number of miles you drive your car. Then enter the average number of miles for the selected time period. The calculator will use this figure to forecast your periodic fuel expenditures.

Life years:Life years:Years to calculate lifetime costs :Number of years to calculate lifetime costs:

Number of years to calculate lifetime costs:

Enter the number of years you would like the fuel mileage calculator to calculate lifetime fuel expenses for.

Invest ROI:Invest ROI:Expected return on investments:Expected percent return on investments:

Expected percent return on investments:

Enter the annual percentage return you would expect to earn on your investments. Enter as a percentage, but without the percent sign (for .06 or 6%, enter 6). The calculator will use this figure to estimate what would happen if you invested the fuel expense savings realized by switching to a vehicle with a higher mpg rating.

MPG:Miles per gallon:Miles per gallon:Miles per gallon:

Miles per gallon:

Based on your beginning and ending odometer readings and the number of gallons pumped, this is your vehicle's calculated miles per gallon (MPG).

Expense and Comparison Chart

Expense and comparison chart:

This chart will display the calculated daily, monthly, annual, and lifetime fuel expenses based on your car's MPG and on the entered average miles you drive the car per selected period.

To see how much you can save by switching to a car that gets better gas mileage, select a comparison MPG from the menu located at the top of the 2nd column. The chart will automatically recalculate each time you make a new selection.

Now MPGNow MPGCurrent MPGCurrent MPGComp MPGComp MPGCompare MPGCompare MPGSaveSaveSavingsSavings
MPG:MPG:Miles per gallon:Miles per gallon:
Day:Daily:Daily expense:Daily fuel expense:
Mon:Month:Monthly expense:Monthly fuel expense:
Year:Year:Annual expense:Annual fuel expense:
Life:Lifetime:Lifetime expense:Lifetime fuel expense:

If you would like to save the current entries to the secure database, tap or click on the Data tab, select "New Data Record", give the data record a name, then tap or click the Save button. To save changes to previously saved entries, simply tap the Save button. Please select and "Clear" any data records you no longer need.

Feedback AppreciatedFeedback Greatly AppreciatedYour Feedback Would Be Greatly AppreciatedYour Feedback Is Greatly Appreciated


Help and Tools

Help and Tools:

This section, which you can Unstick or Hide in the Calculator Preferences (just above the top of the calculator), contains the following tabs (content too long to fit within bordered frame can be scrolled up and down):

About: Click this tab for an introduction to the calculator.

Instructions: Click this tab for step-by-step instructions for using the calculator.

Terms: Click this tab for a list of the descriptions that are located within each popup help button (info icons).

PCalc: Click this tab for a handy "pocket" calculator you can use when you need to calculate an entry needed for the calculator.

Data: Click this tab to save a set of entries or a note in between visits. Entries and notes will be stored to your web browser's local storage (if supported by your browser of choice), meaning they can only be recalled with the same device and web browser you were using when you saved them. If you'd like to save entries and notes between devices you can do so by subscribing to the Ad-Free Member Version.



Add or remove this page to/from my favorites.

Adjust Calculator Width:

Move the slider to left and right to adjust the calculator width. Note that the Help and Tools panel will be hidden when the calculator is too wide to fit both on the screen. Moving the slider to the left will bring the instructions and tools panel back into view.

Also note that some calculators will reformat to accommodate the screen size as you make the calculator wider or narrower. If the calculator is narrow, columns of entry rows will be converted to a vertical entry form, whereas a wider calculator will display columns of entry rows, and the entry fields will be smaller in size ... since they will not need to be "thumb friendly".

Show/Hide Popup Keypads:

Select Show or Hide to show or hide the popup keypad icons located next to numeric entry fields. These are generally only needed for mobile devices that don't have decimal points in their numeric keypads. So if you are on a desktop, you may find the calculator to be more user-friendly and less cluttered without them.

Stick/Unstick Tools:

Select Stick or Unstick to stick or unstick the help and tools panel. Selecting "Stick" will keep the panel in view while scrolling the calculator vertically. If you find that annoying, select "Unstick" to keep the panel in a stationary position.

If the tools panel becomes "Unstuck" on its own, try clicking "Unstick" and then "Stick" to re-stick the panel.