Fuel Economy Converter — MPG, km/L & L/100km
Convert between MPG (US/UK), km/L and L/100km accurately.
| MPG (US) | 40 |
| MPG (UK) | 48.04 |
| km / L | 17.01 |
| L / 100km | 5.88 |
US and UK gallons differ (3.785 L vs 4.546 L), so a US MPG figure is lower than the same car's UK MPG. L/100km is inverse — lower is better. Calculated in your browser.
Convert a fuel economy figure between US MPG, UK (imperial) MPG, kilometres per litre and litres per 100 km — all four at once. It correctly handles the different US and UK gallon sizes and the inverse relationship of L/100km (where lower is better). Useful when comparing cars across regions. Calculated in your browser.
How to use the Fuel Economy Converter
- Enter a value and choose its unit.
- Read the equivalent in US MPG, UK MPG, km/L and L/100km.
- Compare figures across regions.
Frequently asked questions
Why do US and UK MPG differ?
The US gallon (3.785 L) is smaller than the UK imperial gallon (4.546 L), so the same car shows a lower number in US MPG than in UK MPG even though the fuel use is identical.
Why is lower better for L/100km?
L/100km measures fuel used per distance, the inverse of MPG. Fewer litres to cover 100 km means a more efficient car.