Fuel Efficiency Converter
Convert between MPG (US & UK), litres per 100 km, kilometres per litre, and miles per litre. All values update live — including the inverse L/100km relationship.
How to use this tool
- 1Find the unit you know
Locate the input field for the fuel efficiency unit you have — MPG (US), MPG (UK), L/100km, km/L, or miles/L.
- 2Type the value
Enter your number into the field. All other unit fields update instantly. Note: L/100km is inverse to MPG — higher L/100km means lower MPG.
- 3Copy or compare
Click the copy button next to any value. Check the reference section to see how your vehicle compares to typical efficiency ranges.
Understanding fuel efficiency units
MPG (miles per gallon)
MPG measures how many miles a vehicle can travel on one gallon of fuel. Higher MPG means better fuel economy. The US and UK use different gallon sizes — the Imperial (UK) gallon is about 20% larger, so UK MPG figures are always higher than US MPG for the same vehicle.
L/100km (litres per 100 km)
Used across Europe, Australia, and much of Asia, L/100km measures how many litres of fuel are needed to drive 100 kilometres. Lower numbers mean better efficiency. This unit is inversely related to MPG — as one goes up, the other goes down.
km/L and miles/L
Kilometres per litre (km/L) is used in parts of Asia and South America. Like MPG, higher values mean better efficiency. Miles per litre is less common but useful when buying fuel in litres while measuring distance in miles, as happens in some countries.
Get GEO & AEO tips every week
The Layman SEO newsletter. Plain English updates on what is changing in search - SEO, AEO, and GEO - and what to do about it. One email a week. Unsubscribe any time.
No spam. No paywall content. Unsubscribe with one click.