Home / Specs & Conversions / MPG to L/100km Converter
Specs & ConversionsMPG to L/100km Converter
Comparing a US fuel-economy figure with a European or Asian one? Enter the MPG (US gallons) and we’ll convert it to liters per 100 km and kilometers per liter.
How this calculator works
MPG and L/100km are inverse measures, so the conversion isn’t linear: L/100km = 235.21 ÷ MPG. A higher MPG means a lower L/100km (less fuel used). We also give km/L, which like MPG goes up as the car gets thriftier.
What changes the number
- This uses the US gallon (3.785 L). Imperial (UK) gallons are larger, so UK MPG figures look higher for the same car — don’t mix them.
- L/100km is “lower is better”; MPG and km/L are “higher is better.” It’s easy to flip them by mistake.
- For quick mental math, 235 ÷ MPG is close enough.
Frequently asked questions
Why isn’t the conversion a simple multiplier?
Because the two units measure opposite things — distance per fuel vs fuel per distance. That makes them reciprocals, so you divide a constant (235.21) by the MPG rather than scaling it.
Is this US or Imperial gallons?
US gallons. A UK Imperial gallon is about 20% larger, so a UK “50 mpg” is not the same as a US “50 mpg.” Use the US figure here.
What’s a good L/100km?
Lower is better. An efficient modern car is around 6–8 L/100km; a hybrid can dip to 4–5; large trucks run 12+.