Automotive

MPG Calculator

Calculate miles per gallon, gallons per 100 miles and liters per 100 kilometers from distance and fuel used.

Free online toolWorks in your browserNo sign-up required
Roadmap #31–60

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How to use this mpg calculator

Enter the requested values above and select Calculate. Change any input to compare scenarios.

Formula and method

MPG = miles driven ÷ gallons used. L/100 km ≈ 235.214583 ÷ MPG.

Example

If you drive 360 miles and use 12 gallons, fuel economy is 30 MPG, or about 7.84 L/100 km.

Important assumptions

For the best tank-to-tank estimate, fill the tank to the same level before and after the measured driving period.

Frequently asked questions

What does the MPG Calculator calculate?

Calculate miles per gallon, gallons per 100 miles and liters per 100 kilometers from distance and fuel used.

How does the calculation work?

MPG = miles driven ÷ gallons used. L/100 km ≈ 235.214583 ÷ MPG.

Is this calculator free?

Yes. ERICH Calculators is free to use and no account is required.

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Method, assumptions & corrections

See how formulas, sources and limitations are handled across ERICH Calculators.