Fuel Cost Calculator

Calculate fuel cost for a trip based on distance, fuel price, and fuel efficiency (MPG or L/100km). See cost per mile/km.

This calculator estimates trip fuel cost from three inputs: how far you're driving, your vehicle's fuel efficiency, and the price of fuel. The Use Metric selector switches both which efficiency field is read AND what unit Distance itself is in: in imperial mode Distance is miles and Fuel Needed is Distance divided by MPG (more miles per gallon means less fuel burned for the same trip); in metric mode Distance is kilometers and Fuel Needed is Distance divided by 100, multiplied by L/100km -- here a HIGHER L/100km figure means WORSE efficiency (more fuel burned per 100 km), the reverse relationship from MPG. In both modes Total Fuel Cost is Fuel Needed multiplied by Fuel Price. Cost per Mile and Cost per Kilometer both express the same Total Fuel Cost on a per-unit-distance basis and always move together, but the underlying division uses whichever unit Distance was actually entered in for the active mode (with a 1.60934 km-per-mile conversion applied to derive the other one), not distance itself twice over. Because Total Fuel Cost is a straightforward product of Fuel Needed and Fuel Price, doubling either the trip distance or the fuel price exactly doubles the total cost, all else held equal -- there's no discount or nonlinearity built into the model. Note that the live Fuel Price autofill is priced in dollars per gallon, so switching to Metric mode means you should re-check or override the autofilled price against a per-liter figure.