Unit Conversion

Convert numbers between two units quickly and precisely

Fuel Consumption Converter

Unit Conversion

Convert fuel consumption: l/100km, mpg, and km/l

Fuel consumption is usually stated as liters per 100 kilometers (l/100km) in Europe, while in the US and UK, miles per gallon (mpg) is used – with different references depending on whether the US gallon or the somewhat larger UK gallon is meant. Unlike most units, the relationship here is not linear: l/100km is inversely proportional to mpg and km/l, so a doubled l/100km value doesn't mean half the mpg value, but a different factor.

Key conversion factors:

  • 8 l/100km ≈ 29.4 mpg (US) – a typical midsize car
  • 1 mpg (US) ≈ 235.21 / (l/100km) or 1 mpg (UK) ≈ 282.5 / (l/100km)
  • 1 US gallon = 3.785 liters, 1 UK gallon = 4.546 liters – which is why US mpg and UK mpg differ by about 20% for the same actual consumption
  • Lower l/100km value = higher mpg value and vice versa – the two scales run in opposite directions

Applications:

  • Vehicle comparison: comparing consumption figures between European and US/UK vehicle spec sheets
  • Cost calculation: estimating fuel costs for imported vehicles

The fuel consumption converter makes consumption figures from different markets directly comparable. For pure volume units, use the volume converter.

Frequently asked questions about converting fuel consumption

Since l/100km is inversely proportional to mpg, there's no simple multiplication by a fixed factor. Instead: mpg (US) ≈ 235.21 / (l/100km). A consumption of 8 l/100km therefore equals about 29.4 mpg (US).

The US gallon (3.785 liters) and the UK gallon (4.546 liters) are different sizes. For the same actual consumption, this results in a higher mpg value under the UK definition than under the US definition – the difference is about 20%.

km/l is the reciprocal of l/100km, multiplied by 100: km/l = 100 / (l/100km). For 8 l/100km, that's 100 / 8 = 12.5 kilometers per liter.