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Fuel Consumption Calculator

📍
miles
🚗
MPG

How to Use This Calculator

  1. 1

    Enter the total miles

    For a trip there and back, add both legs: 150 miles each way is 300 miles. For a commute, enter one day of driving and multiply the result by your driving days.

  2. 2

    Use the MPG that fits the trip

    Use your highway figure for open road and your city figure for stop and go driving. An average you measured yourself with the Mileage (MPG) Calculator usually reflects your driving better than the window sticker.

  3. 3

    Convert kilometers first

    The distance box is in miles. Divide kilometers by 1.609: 400 km is about 249 miles.

Formula and Logic

Gallons needed equal distance divided by MPG. The calculator shows the answer to two decimals.

Fuel needed = Distance ÷ MPG

  • •Gallons grow in step with distance: 300 miles at 30 MPG is 10 gallons, and 600 miles is 20.
  • •Each extra MPG saves less as MPG rises: over 300 miles, going from 20 to 25 MPG saves 3 gallons, while going from 40 to 50 MPG saves 1.5.
  • •For a cost, multiply the gallons by your price per gallon.
Vehicle MPGGallons (300 mi)Cost at an example $3.45/gal
20 MPG15.0 gal$51.75
25 MPG12.0 gal$41.40
30 MPG10.0 gal$34.50
35 MPG8.6 gal$29.57
40 MPG7.5 gal$25.88
50 MPG6.0 gal$20.70

Example Calculations

Example 1: Weekend highway trip

Inputs

  • Distance300 miles
  • Vehicle MPG30

Output

Fuel needed10 gallons

A vehicle that gets 30 MPG uses 1 gallon for every 30 miles. Over 300 miles, it needs 10 gallons.

Example 2: Daily commute estimate

Inputs

  • Distance50 miles
  • Vehicle MPG25

Output

Fuel needed2 gallons

50 ÷ 25 = 2 gallons a day, or 10 gallons over a five day week.

Example 3: Long distance drive in a less efficient vehicle

Inputs

  • Distance500 miles
  • Vehicle MPG20

Output

Fuel needed25 gallons

500 ÷ 20 = 25 gallons. The same trip at 30 MPG would need about 16.7, so the lower MPG adds about 8.3 gallons.

Frequently Asked Questions

How many gallons do I need for a 500 mile trip?
Divide the miles by your MPG: 500 ÷ 25 = 20 gallons. At 30 MPG it is about 16.7 gallons and at 20 MPG it is 25. If you are driving there and back, add both legs first: 250 miles each way is 500 miles.
How do I turn the gallons result into a fuel cost?
Multiply the gallons by your price per gallon. 20 gallons at an example price of $3.50 is $70.00. The table on this page does the same at an example $3.45: 300 miles at 30 MPG is 10 gallons, or $34.50. The Gas Cost Calculator does both steps at once.
How far can I drive on one tank?
Multiply your tank size by your MPG. A 14 gallon tank at 30 MPG covers about 420 miles. If you plan to refuel with a quarter tank left, count on 10.5 gallons, or about 315 miles between stops.
Should I use city or highway MPG?
Use the one that matches the trip, because the gap changes the answer: 300 miles is 10 gallons at 30 MPG but 12.5 gallons at 24 MPG. For mixed driving, use the average you measure with the Mileage (MPG) Calculator.
How much fuel does my commute use in a week?
Enter one day's round trip and multiply the result by your driving days. A 40 mile round trip at 25 MPG is 1.6 gallons a day, or 8 gallons over five days. The Commute Cost Calculator turns that into weekly, monthly and yearly costs.
My trip is in kilometers. What do I enter?
Convert to miles first by dividing by 1.609. An 800 km trip is about 497 miles, which at 30 MPG needs about 16.6 gallons. To get liters, multiply gallons by 3.785: about 62.7 liters.

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