About the Fuel Consumption Converter
Fuel economy is quoted in different ways around the world. Europe, Australia and most of Asia use litres per 100 kilometres, where a lower number is better. India and some other countries prefer kilometres per litre. The US uses miles per US gallon, and the UK uses miles per Imperial gallon, which is about 20 percent larger. This converter takes a figure in one of these four units and shows the other three straight away, so you can compare a car review from another country, convert a trip computer reading or check a manufacturer's claim.
Updated October 2026
How to use the Fuel Consumption Converter
- 1Enter your fuel economy figure.
- 2Choose the unit it is in.
- 3Read the other three units in the result.
- 4Remember that for L/100 km a smaller number means better economy.
- 5Copy the line to share or compare.
Quick reference
- 5 L/100 km is about 47 US mpg or 56.5 UK mpg.
- 7 L/100 km is about 33.6 US mpg or 40.4 UK mpg.
- 8 L/100 km is about 29.4 US mpg or 35.3 UK mpg.
- 10 L/100 km is about 23.5 US mpg or 28.2 UK mpg.
- 12.5 km/L is 8 L/100 km.
Why the unit matters
The mpg scale can mislead. Going from 10 to 20 mpg saves more fuel than going from 40 to 50 mpg, even though the second gain looks bigger. Litres per 100 km avoids the problem because equal differences mean equal fuel savings per distance. Consumer groups in the US have called for a gallons-per-100-miles label for this reason.
To compare two cars from different countries, convert both to the same unit first. A German estate that uses 5.8 L/100 km is about 40.6 US mpg, which beats a US pickup rated at 22 mpg that uses 10.7 L/100 km. Over 15,000 km the difference is about 740 litres of fuel. Multiplying that by the local fuel price shows the real cost of the gap, and the Trip Cost Calculator can do that final step for any distance you choose.
Next steps
Use the Fuel Economy Calculator to work out your car's real figure from a tank of fuel, the Trip Cost Calculator to turn it into money, the Mileage Calculator for reimbursement and the Unit Converter for litres and gallons.
Features
- L/100 km, km/L, US mpg and UK mpg
- All conversions in one view
- Exact formulas, not rough tables
- Clear message for zero
- Great for comparing foreign car reviews
- No data leaves your device
Frequently asked questions
How do I convert MPG to L/100 km?
Divide 235.215 by the mpg figure if it is in US gallons, or 282.481 if it is in UK gallons. A car doing 30 US mpg uses 235.215 ÷ 30 = 7.84 litres per 100 km.
Why are UK and US mpg different?
The Imperial gallon used in the UK is 4.546 litres, while the US gallon is 3.785 litres. A car travels further on a bigger gallon, so the same car looks about 20 percent better in UK mpg than in US mpg.
What is a good fuel economy?
For petrol cars a small hatchback manages around 5 to 6 L/100 km (40 to 47 US mpg), an average car 7 to 8 L/100 km and a large SUV 10 to 14 L/100 km. Hybrids reach 4 to 5 L/100 km, and diesel cars are often a little lower than petrol equivalents.
Why does L/100 km go down when economy improves?
It measures fuel used per distance, not distance per fuel. The smaller the number, the less fuel you burn. mpg and km/L work the other way round.
How do I convert km/L to L/100 km?
Divide 100 by the km/L figure. A car that does 12.5 km/L uses 8 litres per 100 km. The conversion works both ways with the same formula.
Are the numbers on the car's computer accurate?
They are usually within a few percent but often read slightly low. Fill the tank, reset the trip meter, and the next time you fill up, divide the fuel by the distance for a more reliable figure.