Fuel cost calculator
Fuel cost is distance divided by economy times price. The only trap is mixing metric and imperial economy units.
L/100km
per litre
Fuel cost for the trip
55.69
- Cost each if shared
- 55.69
- Fuel used
- 33.75
- Cost per kilometre
- 0.1238
- Annual cost at that frequency
- 13 921.88
- Economy in US mpg
- 31.36
- Economy in imperial mpg
- 37.66
- Cost per 100 km
- 12.38
Show the working
- Distance = 450
- Fuel economy = 7.5
- Fuel price = 1.65
- Trips per year = 250
- People sharing = 1
- Fuel used = 450 * 7.5 / 100 = 33.75
- Fuel cost for the trip = 33.75 * 1.65 = 55.6875
- Cost per kilometre = 450 > 0 ? 55.6875 / 450 : 0 = 0.123 75
- Cost each if shared = 55.6875 / 1 = 55.6875
- Annual cost at that frequency = 55.6875 * 250 = 13 921.9
- Economy in US mpg = 7.5 > 0 ? 235.214583 / 7.5 : 0 = 31.3619
- Economy in imperial mpg = 7.5 > 0 ? 282.480936 / 7.5 : 0 = 37.6641
- Cost per 100 km = 7.5 * 1.65 = 12.375
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
Scenarios & local history
Compare a saved scenario
Recent calculations
The formula
- litres = distance x L/100km / 100
- US mpg = 235.214 583 / (L/100 km); imperial mpg = 282.480 936 / (L/100 km)
The 235 and 282 constants are exact conversions, not approximations — they come from the exact definitions of the gallon and the mile.