Miles per gallon from distance and fuel used — with L/100km, km per litre and cost per mile alongside.
Cost per mile = price per gallon / MPG. Leave the price at 0 to skip cost figures.
miles per gallon
How to use this tool
Use a full tank-to-tank distance for the most accurate figure.
Gallons to refill, from the pump reading.
The two gallons differ, so L/100km conversions use the right one.
In Advanced, to get cost per mile and per 100 miles.
Formula & worked example
300 miles on 10 US gallons = 30 MPG = 7.84 L/100km = 12.75 km/L. At $3.50 per gallon, that is $35 per tank and about $0.117 per mile.
Limitations — read this before you rely on it
Tank-to-tank MPG varies with driving style, traffic, temperature, tyre pressure and load; a single fill is noisy, so average over several tanks for a reliable figure. This calculator measures fuel actually used, not the manufacturer's test-cycle figure.
Frequently asked questions
Divide miles driven by gallons used: 300 miles / 10 gallons = 30 MPG.
For US MPG, divide 235.214583 by the MPG. For UK MPG, divide 282.480936 by it.
Yes: 4.546 litres versus 3.785 litres, so the same car shows a higher MPG number in the UK.
It depends on the vehicle: roughly 30+ MPG is good for a petrol car, 50+ for a hybrid, and far higher for electric cars measured in MPGe.
Official figures come from standardised test cycles; real driving, cold starts and short trips usually give lower MPG.