Fuel Cost Calculator — Trip Gas & Petrol Cost
Estimate what a trip costs in fuel from distance, fuel economy and price — miles or km, mpg, L/100km or km/L — split per passenger. Free, in your browser.
🔒 Calculated in your browser — nothing is uploaded.
What a trip costs in fuel
Enter the distance, your vehicle's fuel economy and the fuel price, and see how much fuel the trip uses and what it costs. Mix and match units — miles or kilometres, mpg, L/100km or km/L, and a price per gallon or per litre — so it works wherever you drive. Split the total between passengers to get a per-person share.
How it's worked out
Fuel used = distance ÷ economy, and cost = fuel used × price, with units converted consistently behind the scenes. It covers fuel only — tolls, parking and wear are not included. Everything is calculated in your browser.
Frequently asked questions
How do I calculate the gas cost of a trip?
Divide the distance by your fuel economy to get the fuel used, then multiply by the price per unit. 100 miles at 30 mpg is 3.33 gallons — about $13.33 at $4/gallon.
Which units are supported?
Distance in miles or km; economy in mpg (US), mpg (UK), L/100km or km/L; price per US gallon or per litre. A UK (imperial) gallon is about 20% larger than a US one, so pick the mpg your car is quoted in — reading one as the other is a fifth of the tank.
Can it split the cost for a carpool?
Yes. Set the number of people and it shows the total plus the cost per person.