How the l/100 km to mpg converter works
Canadian fuel consumption is commonly expressed in litres per 100 kilometres, while vehicle listings and cross-border comparisons may use US or Imperial miles per gallon. Showing both MPG standards prevents a common gallon-size error.
Calculation method
Every input is converted to L/100 km, then to km/L, US MPG, and Imperial MPG using fixed conversion constants. Optional trip distance multiplies consumption by kilometres travelled, and optional price multiplies the resulting litres.
US MPG = 235.214583 ÷ L/100 km. Imperial MPG = 282.480936 ÷ L/100 km. km/L = 100 ÷ L/100 km.Assumptions and counting rules
- Fuel economy must be greater than zero because reciprocal conversions divide by the input.
- Trip cost assumes the entered average consumption and fuel price remain constant.
- Displayed values are rounded to three decimal places; calculations retain more precision.
Practical examples
8 L/100 km
Equals about 29.402 US MPG or 35.310 Imperial MPG.
The two MPG values differ because the gallons differ.
40 US MPG
Equals about 5.880 L/100 km.
Useful for comparing a US vehicle listing.
500 km trip
At 8 L/100 km, the estimate is 40 litres.
At $1.60/L, the estimated fuel cost is $64.
Common mistakes
- Using the Imperial formula for a US MPG listing.
- Treating L/100 km as directly proportional to MPG instead of reciprocal.
- Interpreting a rated laboratory value as a guaranteed real-world result.
Edge cases
- Very efficient vehicles produce high MPG because the relationship is reciprocal.
- Zero is rejected because it would imply infinite distance per unit of fuel.
- Weather, speed, load, route, and driving style can change actual consumption.
Questions specific to this tool
Which MPG does Canada use?
Canadian fuel-consumption labels use L/100 km. If MPG appears, confirm whether it means US or Imperial gallons.
Why does lower L/100 km mean better efficiency?
The measure states how many litres are used to travel 100 km, so a smaller amount means less fuel.
Is the trip cost exact?
No. It is a planning estimate based on constant average consumption and the price you enter.
Last reviewed: August 7, 2026 · Method version 1.0.0