Gas Mileage Calculator

Divide the number of miles driven by the gallons of fuel used. For example, if you drove 300 miles and used 10 gallons, your fuel economy is 30 MPG. Fill up your tank completely, drive normally, then fill up again and note the miles traveled and fuel added.

For new cars, 30 MPG combined is generally considered good. Compact and midsize sedans often achieve 35–45 MPG, while SUVs and trucks typically range from 18–28 MPG. Hybrid and electric vehicles can exceed 50 MPGe. The EPA's fueleconomy.gov lets you compare real-world MPG across vehicle models.

Use the formula: L/100km = 235.215 ÷ MPG. So 30 MPG equals 235.215 ÷ 30 = 7.84 L/100km. Note that a lower L/100km number means better fuel economy, while a higher MPG number means better economy — the scales run in opposite directions.