Gas Mileage Calculator
Calculate MPG from miles and gallons.
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Copy or share after running the tool. Saved tools and settings stay in this browser.
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Calculate gas mileage
Fuel economy is easier to trust when you calculate it from real fill-up numbers. Enter miles driven and gallons used to get MPG, plus metric equivalents for comparison. It is helpful for tracking vehicle efficiency, checking changes after maintenance and comparing driving conditions.
Use real trip or tank data
For the cleanest estimate, fill the tank, reset the trip counter, then use miles driven and gallons added at the next fill.
Frequently asked questions
What is MPG?
MPG means miles per gallon, calculated as miles driven divided by gallons used.
Why show liters per 100 km?
That is a common fuel economy format outside the US.
Can I compare multiple tanks?
Yes. Calculate each tank separately or use totals across several fill-ups.