km/L to L/100km Converter
Convert kilometres per litre to litres per 100 km. Results update as you type; exact factors shown.
One kilometres per litre is 100 litres per 100 km — see the exact factor, not a rounded rule of thumb.
How the km/l to l/100km converter works
Fuel economy is an inverse quantity: lower L/100 km is better, higher mpg is better. mpg (US) = 235.215 / (L/100 km) because a US gallon is 3.785 L and a mile 1.609 km; mpg (UK) = 282.481 / (L/100 km) with the 4.546 L imperial gallon. UK mpg figures are therefore always 20% higher than US mpg for the same car.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common fuel economy conversions
| From | To | Units |
|---|---|---|
| 5 km/L | 20 L/100 km | kilometres per litre to litres per 100 km |
| 8 km/L | 12.5 L/100 km | kilometres per litre to litres per 100 km |
| 10 km/L | 10 L/100 km | kilometres per litre to litres per 100 km |
| 12 km/L | 8.3333 L/100 km | kilometres per litre to litres per 100 km |
| 14 km/L | 7.1429 L/100 km | kilometres per litre to litres per 100 km |
| 16 km/L | 6.25 L/100 km | kilometres per litre to litres per 100 km |
| 18 km/L | 5.5556 L/100 km | kilometres per litre to litres per 100 km |
| 20 km/L | 5 L/100 km | kilometres per litre to litres per 100 km |
| 25 km/L | 4 L/100 km | kilometres per litre to litres per 100 km |
| 30 km/L | 3.3333 L/100 km | kilometres per litre to litres per 100 km |
| 40 km/L | 2.5 L/100 km | kilometres per litre to litres per 100 km |
| 50 km/L | 2 L/100 km | kilometres per litre to litres per 100 km |
Units in this converter and their exact factors
| Unit | Symbol | To L/100 km |
|---|---|---|
| litres per 100 km | L/100 km | x |
| kilometres per litre | km/L | 100÷x |
| miles per imperial gallon | mpg (UK) | 282.480936÷x |
| miles per US gallon | mpg (US) | 235.214583÷x |
FAQFrequently asked questions about fuel economy conversion
How do I convert km/L to L/100km?
Divide 100 by the figure. 20 km/L is 5 L/100km.
What is a good km/L?
Over 18 km/L is efficient for a petrol car; hybrids exceed 25.
Why does Australia use L/100km?
Because fuel used per distance scales linearly with cost, which km/L does not.
What is 12 km/L in L/100km?
8.33 L/100km.
Which is easier to compare?
L/100km, because the difference between 6 and 7 means the same everywhere on the scale.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.