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The MPG Calculator helps you figure out your vehicle's fuel economy and plan trip costs. Whether you track consumption in miles per gallon, liters per 100 kilometers, or kilometers per liter, this tool handles the conversions automatically.
This calculator works with five connected variables: distance traveled, fuel used, fuel economy (efficiency), fuel price, and total trip cost. You provide any two values from the first group (distance, fuel used, fuel economy), and the calculator solves for the missing one. If you also enter the fuel price, it computes your total fuel cost.
Fuel economy can be measured two ways. In the US, drivers use miles per gallon (MPG), where higher numbers mean better efficiency. A typical car gets 25-30 MPG. In most other countries, the standard is liters per 100 kilometers (L/100km), where lower numbers are better. A fuel-efficient car uses about 6-8 L/100km. The calculator converts between these systems instantly.
Fill in your odometer reading or trip distance in kilometers or miles.
Enter the amount of fuel you used in liters, US gallons, or UK gallons.
The calculator will compute your fuel economy. Or leave distance blank and enter fuel economy to find the distance you can travel.
Toggle advanced mode to enter fuel price per unit and calculate total trip cost.
Say you drove 500 km and filled up 40 liters. Your fuel economy is 8.0 L/100km (or about 29.4 US MPG). If fuel costs $1.50 per liter, that trip cost you $60. For a road trip of 1,200 miles in a car that gets 30 MPG, you would need 40 gallons. At $3.50 per gallon, budget $140 for fuel.
Use the full tank method: fill up completely, drive, then fill up again. The second fill amount is your fuel used.
Measure over longer distances (at least 100 km or 60 miles) for more reliable fuel economy readings.
Fuel economy varies with driving conditions. Highway driving gives better MPG than city driving.
Keep in mind that US gallons (3.785 L) are smaller than UK gallons (4.546 L), so US MPG and UK MPG are different.
What is a good MPG?
For a gasoline car, 30+ MPG (7.8 L/100km or less) is considered good. Hybrids often achieve 50+ MPG. Trucks and SUVs typically range from 15-25 MPG.
How do I convert between MPG and L/100km?
Divide 235.215 by your MPG to get L/100km, or divide 235.215 by your L/100km to get MPG. For example, 30 MPG equals about 7.84 L/100km.