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.
Measure your car’s real economy from a fill-up
Fill the tank and note the odometer. Next time you fill up, note it again and how much fuel went in: the distance between the two readings over that fuel is what the car actually does.
Fuel only: tolls, parking and wear are not included, and the car is taken to use fuel at the efficiency typed, adjusted for the driving style.
| If the price is | Total cost |
|---|---|
| $3.20/gal (US) (-20%) | $10.67 |
| $3.60/gal (US) (-10%) | $12.00 |
| $4.00/gal (US) (0%) | $13.33 |
| $4.40/gal (US) (+10%) | $14.67 |
| $4.80/gal (US) (+20%) | $16.00 |
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, km/L or L/mi, 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. The “Fuel used” figure also gives the other volume — litres beside US gallons, or the other way round — and if you do not know your car's economy, “Measure your car’s real economy from a fill-up” works it out from two odometer readings and the fuel that went in, with “Use this figure” to put it in the box.
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, km/L or L/mi; 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 puts the fuel figure off by a fifth.
Can it split the cost for a carpool?
Yes. Set the number of people and it shows the total plus the cost per person.
Is the distance one way or there and back, and does driving style count?
One way — the field is labelled "One-way distance". Tick "Round trip — drive back the same way" and the trip is doubled for you. How you drive changes the answer too: the "Driving style" select starts on "Normal (as rated)", which uses the economy you typed, and its Aggressive and Eco options raise or lower the fuel by the percentage shown in each.
Can it cost a regular commute, compare two cars, or show what a price change does?
Yes. Type how many times a week you make the trip into “Trips per week”, and “Per month” and “Per year” appear beside the total. Fill in “Second car’s efficiency, same unit” and the same trip is costed for that car too, with “Second car minus first” beside it. The cost per mile or per kilometre of the whole drive, round trip included, sits with the total, and a table headed “If the pump price moves” prices the same trip at the typed price moved up and down in percentage steps.
What if I don't know my car's real fuel economy?
Measure it. Open “Measure your car’s real economy from a fill-up”, type the odometer at the last fill-up, the odometer now and the fuel that went in this time, in litres or US gallons, and the page gives the economy in the unit selected above; “Use this figure” puts it in the efficiency box. The readings are not added to the link.