Europe and much of Asia rate cars in litres per 100 km, while the U.S. uses miles per U.S. gallon and the UK miles per imperial gallon.
How to use the Fuel Economy Converter
- Consumption
- Every result field is editable: type into Miles per gallon (US) or any other result and Consumption plus every other field update to match.
Results update as you type, and every field accepts the units shown in its menu.
How it works
Each value is the reciprocal of consumption, scaled by the length of a mile and the size of a gallon.
What each result means
- Miles per gallon (US) = 235.214583 ÷ [Consumption]
- Miles per gallon (UK) = 282.480936 ÷ [Consumption]
- Kilometres per litre = 100 ÷ [Consumption]
- Gallons (US) per 100 miles = [Consumption] × 0.42514371
Example values
How the main result changes when Consumption changes and everything else stays at the example values above:
| Consumption (L/100 km) | Miles per gallon (US) (mpg) |
|---|---|
| 3.5 | 67.2 |
| 5.25 | 44.8 |
| 7 | 33.6 |
| 8.75 | 26.9 |
| 10.5 | 22.4 |
| 14 | 16.8 |
Formula
mpg (US) = 235.215 ÷ (L/100 km)mpg (UK) = 282.481 ÷ (L/100 km)km/L = 100 ÷ (L/100 km)Worked example
Inputs — Consumption: 7 L/100 km.
Results — Miles per gallon (US) = 33.6 mpg; Miles per gallon (UK) = 40.4 mpg; Kilometres per litre = 14.29 km/L; Gallons (US) per 100 miles = 2.98 gal/100 mi.
Frequently asked questions
Why is the conversion not linear?
L/100 km is fuel per distance; mpg is distance per fuel, its inverse.
Why are UK mpg figures higher?
An imperial gallon is 20% larger than a U.S. gallon.
What formula does the Fuel Economy Converter use?
mpg (US) = 235.215 ÷ (L/100 km).