L/100km to US MPG Converter
Convert litres per 100 km to US miles per gallon. Results update as you type; exact factors shown.
One litres per 100 km is 235.2146 miles per US gallon — see the exact factor, not a rounded rule of thumb.
How the l/100km to us mpg 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.
Australia is fully metric under the National Measurement Act 1960; imperial units appear only in trade with the US and in older documents.
Common fuel economy conversions
| From | To | Units |
|---|---|---|
| 3 L/100 km | 78.4049 mpg (US) | litres per 100 km to miles per US gallon |
| 4 L/100 km | 58.8036 mpg (US) | litres per 100 km to miles per US gallon |
| 5 L/100 km | 47.0429 mpg (US) | litres per 100 km to miles per US gallon |
| 6 L/100 km | 39.2024 mpg (US) | litres per 100 km to miles per US gallon |
| 7 L/100 km | 33.6021 mpg (US) | litres per 100 km to miles per US gallon |
| 8 L/100 km | 29.4018 mpg (US) | litres per 100 km to miles per US gallon |
| 9 L/100 km | 26.135 mpg (US) | litres per 100 km to miles per US gallon |
| 10 L/100 km | 23.5215 mpg (US) | litres per 100 km to miles per US gallon |
| 12 L/100 km | 19.6012 mpg (US) | litres per 100 km to miles per US gallon |
| 15 L/100 km | 15.681 mpg (US) | litres per 100 km to miles per US gallon |
| 20 L/100 km | 11.7607 mpg (US) | litres per 100 km to miles per US gallon |
| 25 L/100 km | 9.4086 mpg (US) | litres per 100 km to miles per US gallon |
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
What is 8 L/100km in US mpg?
29.4 mpg.
Why is the US figure lower than the UK one?
Because the US gallon is smaller, so fewer miles fit in it.
Is the conversion linear?
No — the two are reciprocals, so halving consumption doubles mpg.
Which is more useful?
L/100km scales with fuel saved, which is why most of the world uses it.
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 Measurement Institute (NMI) — Australia's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.