Kilometres per litre — km/L — is the way fuel economy is quoted in much of Asia, Latin America and other markets: how many kilometres a vehicle travels on one litre of fuel. Higher is better. Europe uses litres per 100 km, the United States uses miles per gallon, and the three scales do not line up, which makes comparing cars across markets harder than it should be. This calculator finds km/L from a fill-up, converts it into the other two scales, and shows how far a tank will take you.
How to use the kilometers per liter calculator
- Choose what you know: either the distance driven and the fuel used, or a km/L figure you already have.
- Enter the numbers. Distance can be in km or miles and fuel in litres or gallons.
- Enter the tank size to see the range on a full tank.
- Read the results in km/L, L/100 km, US mpg and UK mpg.
The inverse scale has its own page, the liters per 100 km calculator. For general conversions use the fuel economy converter, and to turn economy into money try the fuel cost calculator.
Kilometers per liter formula
L/100 km = 100 ÷ (km/L)
US mpg = 2.35215 × km/L
UK mpg = 2.82481 × km/L
Range = tank size (L) × km/L
- 2.35215 = 3.785411784 L per US gallon ÷ 1.609344 km per mile
- 2.82481 = 4.54609 L per imperial gallon ÷ 1.609344 km per mile
Worked example: 500 km on 40 litres
- Fuel economy: 500 ÷ 40 = 12.5 km/L.
- Litres per 100 km: 100 ÷ 12.5 = 8.0.
- US mpg: 12.5 × 2.35215 = 29.4; UK mpg: 12.5 × 2.82481 = 35.3.
- Range on a 50-litre tank: 50 × 12.5 = 625 km.
Conversion table
Each row is calculated with the formulas above.
| Kilometres per litre | Litres per 100 km | US mpg | UK mpg |
|---|---|---|---|
| 6 km/L | 16.7 L/100 km | 14.1 mpg (US) | 16.9 mpg (UK) |
| 8 km/L | 12.5 L/100 km | 18.8 mpg (US) | 22.6 mpg (UK) |
| 10 km/L | 10.0 L/100 km | 23.5 mpg (US) | 28.2 mpg (UK) |
| 12 km/L | 8.3 L/100 km | 28.2 mpg (US) | 33.9 mpg (UK) |
| 15 km/L | 6.7 L/100 km | 35.3 mpg (US) | 42.4 mpg (UK) |
| 20 km/L | 5.0 L/100 km | 47.0 mpg (US) | 56.5 mpg (UK) |
| 25 km/L | 4.0 L/100 km | 58.8 mpg (US) | 70.6 mpg (UK) |
Measuring your own km/L
The most accurate way is the full-tank method: fill the tank, reset the trip meter, drive normally, then fill again and divide the distance on the trip meter by the litres it takes to refill. Do this over several tanks and average the results, because a single tank can be skewed by the way the pump clicks off or by a long highway run. Trip computers are convenient, but they can read a few percent optimistic, so check yours against the full-tank figure now and then.
Fuel economy changes with conditions. City driving, short trips, cold weather, heavy loads, roof racks, under-inflated tires and fast highway speeds all lower km/L, and gentle driving and steady speeds raise it. When comparing cars, be sure the figures are measured on the same test cycle; official numbers are normally better than real-world results.
To see how much a better km/L is worth, use the gas mileage calculator to track your tanks and the fuel cost calculator to price a trip.
Sources
Unit definitions: 1 US gallon = 3.785411784 litres, 1 imperial gallon = 4.54609 litres and 1 mile = 1.609344 km, all exact (NIST Handbook 44 / the UK Weights and Measures Act). The conversion factors 2.35215 and 2.82481 are derived from these definitions; table values were computed from the formulas shown.
Frequently asked questions
How do I calculate km/L?
Divide the distance driven in kilometres by the fuel used in litres. A car that covers 500 km on 40 litres gets 12.5 km/L.
How do I convert km/L to mpg?
US mpg = km/L × 2.35215; UK mpg = km/L × 2.82481. So 10 km/L is 23.5 US mpg or 28.2 UK mpg.
How do I convert km/L to L/100 km?
Divide 100 by the km/L figure: 12.5 km/L is 100 ÷ 12.5 = 8 litres per 100 km. The conversion works the same way in the other direction.
Why are US and UK mpg different?
The imperial (UK) gallon is 4.54609 litres, larger than the US gallon of 3.785 litres, so the same car has a higher mpg figure in UK terms — about 20% higher.
Is a higher km/L better?
Yes: more distance per litre means lower fuel cost. For L/100 km the reverse is true — lower is better.