Fuel Economy Converter

Convert fuel consumption between US mpg, UK mpg, liters per 100 kilometers and kilometers per liter.

How to use the Fuel Economy Converter

  1. Type the value you want to convert in the first box.
  2. Choose the unit you are converting from and the unit you want to convert to.
  3. Read the result instantly. Use the swap button to reverse the direction, or copy the result with one click.

Popular fuel economy conversions

ConversionResultFormula
Miles per gallon (US) to liters per 100 km1 mpg (US) = 235.215 L/100 kmliters per 100 km = 235.21458 ÷ miles per gallon (US)
Liters per 100 km to miles per gallon (US)1 L/100 km = 235.215 mpg (US)miles per gallon (US) = 235.21458 ÷ liters per 100 km
Miles per gallon (US) to kilometers per liter1 mpg (US) = 0.425144 km/Lkilometers per liter = miles per gallon (US) × 0.42514371
Kilometers per liter to miles per gallon (US)1 km/L = 2.35215 mpg (US)miles per gallon (US) = kilometers per liter × 2.3521458
Kilometers per liter to liters per 100 km1 km/L = 100 L/100 kmliters per 100 km = 100 ÷ kilometers per liter
Liters per 100 km to kilometers per liter1 L/100 km = 100 km/Lkilometers per liter = 100 ÷ liters per 100 km
Miles per gallon (UK) to liters per 100 km1 mpg (UK) = 282.481 L/100 kmliters per 100 km = 282.48094 ÷ miles per gallon (UK)
Liters per 100 km to miles per gallon (UK)1 L/100 km = 282.481 mpg (UK)miles per gallon (UK) = 282.48094 ÷ liters per 100 km
Miles per gallon (US) to miles per gallon (UK)1 mpg (US) = 1.20095 mpg (UK)miles per gallon (UK) = miles per gallon (US) × 1.2009499
Miles per gallon (UK) to miles per gallon (US)1 mpg (UK) = 0.832674 mpg (US)miles per gallon (US) = miles per gallon (UK) × 0.83267418

Supported fuel economy units

UnitSymbolEqual to
Kilometer per literkm/L1 km/L
Liter per 100 kmL/100 kmsee formula
Mile per gallon (US)mpg (US)0.42514371 km/L
Mile per gallon (UK)mpg (UK)0.35400619 km/L
Mile per litermi/L1.609344 km/L

Two ways to measure fuel use

Miles per gallon and kilometers per liter measure distance per unit of fuel, so a higher number is better. Liters per 100 kilometers measures fuel per distance, so a lower number is better. Because one is the inverse of the other, the conversion is a division, not a multiplication:

  • L/100 km = 235.215 ÷ mpg (US)
  • L/100 km = 282.481 ÷ mpg (UK)
  • L/100 km = 100 ÷ km/L

A UK gallon is larger than a US gallon, so the same car has a higher mpg figure in the UK. A car that does 30 mpg (US) does about 36 mpg (UK).

Frequently asked questions

How do I convert mpg to L/100 km?

Divide 235.215 by the US mpg figure. For example, 30 mpg (US) is 235.215 ÷ 30 = 7.84 L/100 km.

Why are US and UK mpg different?

The UK (imperial) gallon is 4.546 liters and the US gallon is 3.785 liters, so a UK mpg figure is about 20% higher for the same car.

What is a good fuel consumption figure?

For a petrol car, around 5 to 7 L/100 km (34 to 47 US mpg) is efficient. Hybrids often achieve 4 to 5 L/100 km.

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