Fuel Cost Calculator

Find how much fuel a trip will cost, in US (mpg) or metric (L/100km) units.

⏱ Updated: 17 Sep 2026

Calculator

Free fuel cost calculator: find how much fuel a trip will cost, in US (mpg) or metric (L/100km) units.

Fuel Needed
Total Cost

Enter your trip distance, fuel economy, and fuel price to calculate the cost.

How to Use the Fuel Cost Calculator

Distance, fuel economy, and price per unit are required; flip the unit toggle first if fuel economy is quoted in L/100km rather than mpg, since the two aren't simple reciprocals of each other.

US:     fuel used = distance (mi) ÷ mpg
Metric: fuel used = distance (km) × L/100km ÷ 100

Multiply either by the price per unit and you've got the trip's fuel cost. This Fuel Cost Calculator runs whichever version matches how your vehicle's economy is rated — mpg in the US, L/100km almost everywhere else.