Fuel Efficiency Converter
Convert between fuel economy units.
How to use the Fuel Efficiency Converter
- Type the figure into the Value box; the result updates as you type, with no button to press.
- Choose km/L or MPG (US) in From and in To. The page opens on km/L to MPG (US).
- Read the converted figure below, labelled with the unit you converted into.
Why L/100km is not one of the choices
Kilometres per litre and miles per gallon both measure distance per unit of fuel, so one multiplier moves between them: a km/L figure times 2.352145 gives US MPG. Litres per 100 km inverts the scale, so it needs a reciprocal instead. Divide 100 by the km/L figure.
Common figures side by side
The middle column is what this converter returns; the right-hand one is the reciprocal you work out yourself. Lower is better in that column and higher is better in the other two.
| km/L | MPG (US) | L/100km |
|---|---|---|
| 8 | 18.82 | 12.50 |
| 10 | 23.52 | 10.00 |
| 12 | 28.23 | 8.33 |
| 15 | 35.28 | 6.67 |
| 20 | 47.04 | 5.00 |
Frequently asked questions
Which unit is used where?
Kilometres per litre in Korea and Japan, miles per gallon in the US and UK, and litres per 100 km across most of Europe.
Why do MPG figures differ between the US and UK?
Because the gallons differ. The imperial gallon is about 20 percent larger, so the same car shows a higher MPG figure in the UK.
How many MPG is 15 km/L?
About 35.28 US MPG. As a rough check, multiply any km/L figure by 2.35, or divide an MPG figure by 2.35 to come back.
Is the MPG here the US gallon or the imperial one?
The US gallon, at 3.785 litres. The imperial gallon used in the UK is about 20 percent larger, so multiply a US MPG figure by 1.2 for the imperial one.
Can I use it for an electric car?
No. Both units measure litres of liquid fuel, so km per kWh and miles per kWh cannot be converted here.