Fuel Consumption Calculator

Work out fuel consumption instantly with clear inputs, formula shown and shareable results.

About Fuel Consumption Calculator

Consumption in litres per 100 km is fuel divided by distance times 100 — a rate, so lower is better. Kilometres per litre and miles per gallon are efficiencies where higher is better, and one imperial gallon is 4.546 litres while a US gallon is 3.785.

Formula

Fuel consumption

L/100km = litres / km x 100; km/L = km / litres; mpg (imperial) = km/L x 2.825

Worked example

With the default values below, Fuel Consumption Calculator returns Consumption of 6.61. Change any input above and every figure here is recalculated in your browser.

Inputs used

Distance travelled: 620 km
Fuel used: 41 L
Fuel price per litre: 1.62

Results

Consumption: 6.61 L/100km
Economy: 15.12 km/L
Economy: 42.72 mpg
Cost per kilometre: $0.1071

Step by step

1Values used
2Fuel consumption
3Consumption= 6.61 L/100km
4Economy= 15.12 km/L
5Economy= 42.72 mpg
6Cost per kilometre= 0.1071

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Which measure is better?

L/100km scales linearly with fuel used, so a 1 L/100km improvement always saves the same fuel. Improvements in mpg are worth progressively less as the number rises.

Why is imperial mpg higher than US mpg?

The imperial gallon is 20% larger, so the same car reads about 20% more mpg in imperial units.