Fuel Cost Calculator

Work out what a drive will cost in gas from the distance, your car's MPG and the price per gallon, split it between passengers and compare two vehicles, or find your real MPG from a fill-up. Your inputs stay in your browser.

Your trip

What do you want to work out?

One way. Tick round trip below to double it.

Your own figure from a fill-up is more accurate than the EPA rating.

Needed for trip cost; optional for MPG.

Another car's MPG, to see the difference for the same trip.

Since the last time you filled the tank (reset the trip meter at the pump).

From the pump when you fill the tank again.

$31.25 in fuel for 250 miles (8.9 gallons). See full results

Example: a 250-mile drive in a car that gets 28 MPG, with gas at $3.50 a gallon (an illustrative price, not today's). Enter your trip to update.

Fuel cost of your trip

Fuel cost
$31.25
250 miles at $3.50 a gallon
Gas used
8.9 gal
At 28 MPG
Cost per mile
12.5¢
$12.50 per 100 miles

Fuel only: tolls, parking and wear on the car are not included.

How to calculate the fuel cost of a trip

  1. Gallons: divide the distance by your fuel economy: 250 miles ÷ 28 MPG = 8.93 gallons.
  2. Cost: multiply the gallons by the price per gallon: 8.93 × $3.50 = $31.25.
  3. Round trip: double the distance, or tick “Round trip”: $62.50.

Fuel cost = miles ÷ MPG × price per gallon

The cost per mile is the price divided by the MPG: $3.50 ÷ 28 = 12.5 cents a mile. Multiply that by any distance, such as your weekly commute or a year of driving, for a quick estimate.

Fuel cost per 100 miles

Find your car's MPG in the first column and the gas price across the top.

Cost of gas per 100 miles by MPG and price per gallon

MPG$3.00/gal$3.50/gal$4.00/gal$4.50/gal$5.00/gal
15 MPG $20.00$23.33$26.67$30.00$33.33
20 MPG $15.00$17.50$20.00$22.50$25.00
25 MPG $12.00$14.00$16.00$18.00$20.00
30 MPG $10.00$11.67$13.33$15.00$16.67
35 MPG $8.57$10.00$11.43$12.86$14.29
40 MPG $7.50$8.75$10.00$11.25$12.50
50 MPG $6.00$7.00$8.00$9.00$10.00

Comparing vehicles

Fuel savings shrink as MPG rises. Over 1,000 miles at $3.50 a gallon, going from 20 to 30 MPG saves $58.33 ($175.00 → $116.67), but going from 30 to 40 MPG saves only $29.17. That is because cost follows gallons per mile, not miles per gallon. Enter a second MPG in “Compare with” to see the difference for your own trip.

How to work out your real MPG

  1. Fill the tank and reset the trip meter.
  2. Drive as usual until you need gas, then fill the tank again.
  3. Divide the miles on the trip meter by the gallons it took to refill: 320 ÷ 11.2 = 28.6 MPG, or 8.2 liters per 100 km.

Your MPG can differ from the EPA rating on the window sticker. How and where you drive, maintenance, weather, air conditioning, load and fuel all affect it; the ratings are best used to compare vehicles (FuelEconomy.gov: your mileage will vary). Averaging a few fill-ups gives a steadier figure for trip estimates.

Assumptions and limits

  • Fuel only. Tolls, parking, maintenance, tires and depreciation are not included.
  • One MPG and one gas price for the whole trip. Highway and city driving, traffic, hills and price changes along the route will move the result.
  • Gasoline or diesel priced per gallon. Electric vehicles, which use kilowatt-hours, are not covered.

Methodology and testing

Gallons = miles ÷ MPG; cost = gallons × price; MPG = miles ÷ gallons. Liters per 100 km use the exact US gallon (3.785411784 liters) and mile (1.609344 km). Automated tests check hand-worked examples, round trips, cost splitting, vehicle comparisons and the metric conversion. How we build and test calculators.

Sources

  • Your Mileage Will Vary, FuelEconomy.gov, U.S. Department of Energy and U.S. Environmental Protection Agency. EPA fuel economy ratings are useful for comparing vehicles but may not predict your MPG; driving habits, conditions, maintenance, weather, accessories, load and fuel all affect it.
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