Fuel Economy Converter

Verified formula Updated Jun 2026 Private — runs on your device

Verified formula Private

Litres per 100 km (L/100km)

6.667

Kilometres per litre (km/L): 15.000
Miles per gallon, US (mpg): 35.282

For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.

How to use the Fuel Economy Converter

The Fuel Economy Converter works out your litres per 100 km (l/100km), along with 2 related figures in an instant. Enter fuel economy value and from unit and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.

Enter the fuel economy value.
Choose the from unit.
Read off your litres per 100 km (l/100km), together with kilometres per litre (km/l) and miles per gallon, us (mpg) — the calculator updates automatically, with no button to press.

Worked example

For example, with fuel economy value of 15 and from unit of Kilometres per litre (km/L), the litres per 100 km (l/100km) is 6.667.

Inputs used
Fuel economy value	15
From unit	Kilometres per litre (km/L)

Results
Litres per 100 km (L/100km)	6.667
Kilometres per litre (km/L)	15.000
Miles per gallon, US (mpg)	35.282

Results are estimates for educational use, not professional advice.

Frequently asked questions

Divide 100 by the km/L value. For example, 15 km/L is 100 ÷ 15 = 6.67 litres per 100 km. The two are reciprocals, not a simple scale.

Multiply US mpg by about 0.4251. So 35 US mpg is roughly 14.9 km/L.

For km/L and mpg, higher is more efficient. For L/100km, lower is more efficient because it uses less fuel per distance.

This uses US miles per gallon. The UK (imperial) gallon is larger, so UK mpg figures are higher for the same real efficiency.

Enter the fuel economy value. Choose the from unit. Read off your litres per 100 km (l/100km), together with kilometres per litre (km/l) and miles per gallon, us (mpg) — the calculator updates automatically, with no button to press.