Three tools in one: calculate your car's fuel consumption from a fill-up, estimate the total fuel cost of any trip, or convert between L/100km, MPG (UK), MPG (US) and km/L. Instant results, no sign-up required.
Choose the mode that matches your need. Calculate mode takes the fuel used (in litres) and distance covered (in km) from a real fill-up or trip — ideal for measuring your car's actual economy. It outputs L/100km, km/L, MPG (UK) and MPG (US) all at once. Trip Cost mode lets you plan ahead: enter a distance, your car's consumption rate and the current fuel price to get the total fuel cost and litres needed. Convert mode translates between any two fuel economy units.
L/100km (litres per 100 kilometres) is the standard metric used in Europe, Australia and most of the world. Lower is better — a 6 L/100km car is more efficient than a 9 L/100km car. MPG (miles per gallon) is used in the UK and USA — higher is better. Note that UK MPG and US MPG use different gallon sizes, so a UK rating of 40 MPG is only equivalent to 33 MPG in US terms.
km/L (kilometres per litre) is used in Japan, India and parts of Latin America — higher is better, like MPG. All four units express the same underlying relationship between distance and fuel; they just invert and scale differently.
The conversion constants (282.48 and 235.21) derive from the number of kilometres in a mile (1.60934) multiplied by the litres in a UK gallon (4.54609) or US gallon (3.78541) respectively.
| L/100km | MPG (UK) | MPG (US) | km/L | Typical Vehicle |
|---|---|---|---|---|
| 4.0 | 70.6 | 58.8 | 25.0 | Hybrid / EV range-extender |
| 5.0 | 56.5 | 47.0 | 20.0 | Small efficient petrol |
| 6.0 | 47.1 | 39.2 | 16.7 | Economy saloon |
| 7.5 | 37.7 | 31.4 | 13.3 | Average family car |
| 9.0 | 31.4 | 26.1 | 11.1 | SUV / larger petrol |
| 12.0 | 23.5 | 19.6 | 8.3 | Large SUV / pick-up truck |
| 15.0 | 18.8 | 15.7 | 6.7 | High-performance / older diesel |