MPG to L/100 km Converter, Fuel Economy

About the MPG to L/100 km Converter

This page converts miles per gallon (MPG) to litres per 100 kilometres (L/100 km), the fuel consumption scale used on European, Canadian, Australian and Chinese car labels. MPG tells you how far one gallon takes you, so a higher number is better. L/100 km tells you how much fuel 100 km costs you, so a lower number is better. The two scales are reciprocals of one another, which is why the conversion divides a constant by your figure instead of multiplying.

For US gallons the constant is 235.214583, which comes straight from the definitions of the mile and the gallon:

$$\text{L/100 km} = \frac{100 \times 3.785411784}{1.609344 \times \text{MPG (US)}} = \frac{235.214583}{\text{MPG (US)}}$$

For imperial (UK) gallons the constant changes to 282.480936, because an imperial gallon is 4.54609 litres:

$$\text{L/100 km} = \frac{100 \times 4.54609}{1.609344 \times \text{MPG (UK)}} = \frac{282.480936}{\text{MPG (UK)}}$$

How to use it

Worked examples

MPG (US) to L/100 km table

MPG (UK) to L/100 km table

Why the scales run opposite ways

MPG is distance divided by fuel and L/100 km is fuel divided by distance. A car that gets twice the MPG uses half the L/100 km. Because of this, improvements look bigger on the MPG scale at the low end: lifting a 15 MPG truck to 20 MPG saves 3.9 L/100 km, while lifting a 40 MPG car to 45 MPG saves only 0.7 L/100 km.

Typical values

A small petrol car at 40 MPG (US) uses about 5.9 L/100 km. A mid-size sedan at 30 MPG (US) uses 7.8 L/100 km, a large SUV at 20 MPG (US) uses 11.8 L/100 km, and a heavy pickup at 15 MPG (US) uses 15.7 L/100 km. A diesel hatchback at 60 MPG (UK) uses 4.7 L/100 km. These figures come from the formula on this page, so you can check any car label yourself.

Estimating fuel for a trip

Multiply L/100 km by the distance in kilometres and divide by 100. A car using 7.84 L/100 km over a 450 km drive burns 450 × 7.84 / 100 = 35.3 litres. In MPG (US) terms that is 30 MPG, so the 280 miles of the same trip would need 9.3 US gallons. The conversion lets you use whichever pump display and trip meter you prefer.

Privacy

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Related tools

The L/100 km to MPG converter runs the same maths the other way. The Fuel Economy Converter shows every unit, and the Volume Converter converts litres and gallons.

Frequently asked questions