How do I convert MPG to L/100 km?

Divide 235.215 by the MPG figure for US gallons, or 282.481 for UK gallons.

Why are US and UK MPG figures different?

A UK (imperial) gallon is 4.546 litres and a US gallon is 3.785 litres, so a car travels further on a UK gallon. Always check which gallon an MPG figure uses before comparing.

Which countries use L/100 km?

Most of Europe, Canada, Australia and many other countries quote fuel consumption in L/100 km; the US uses US MPG and the UK still commonly uses imperial MPG.

MPG to L/100 km Converter

Convert a fuel-economy figure in miles per gallon to litres per 100 km. Choose US or UK gallons first — the same MPG number means different consumption depending on which gallon it uses.

Fuel economy (MPG (US))

7.84

L/100 km

12.75

km per litre

36.03

MPG (UK)

Formula: L/100 km = 235.215 ÷ MPG (US), or 282.481 ÷ MPG (UK). The constants come from 1 mile = 1.609344 km, 1 US gallon = 3.785411784 L and 1 UK gallon = 4.54609 L. Lower L/100 km and higher MPG both mean better economy. To work out MPG from a fill-up, use the MPG Calculator.

MPG to L/100 km chart

MPG	L/100 km (US gal)	L/100 km (UK gal)
10	23.52	28.25
15	15.68	18.83
20	11.76	14.12
25	9.41	11.3
30	7.84	9.42
35	6.72	8.07
40	5.88	7.06
50	4.7	5.65
60	3.92	4.71

Need the other direction? Convert L/100 km to MPG.

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How to use mpg to l/100 km converter

1Choose US gallons or UK (imperial) gallons.
2Enter the fuel economy in MPG.
3Read the result in L/100 km, plus km per litre and the equivalent MPG in the other gallon.
4Use the chart for common MPG figures in both gallon types.

About this tool

MPG measures distance per unit of fuel (higher is better); L/100 km measures fuel per distance (lower is better). Because one is the inverse of the other, the conversion is a division: L/100 km = 235.215 ÷ US MPG, or 282.481 ÷ UK MPG.

Those constants come from exact definitions: 1 mile = 1.609344 km, 1 US gallon = 3.785411784 litres and 1 UK (imperial) gallon = 4.54609 litres. The UK gallon is about 20% larger, so the same car shows a higher MPG figure in the UK than in the US — 30 US MPG is 7.84 L/100 km, while 30 UK MPG is 9.42 L/100 km.

This page converts a figure you already have. To calculate MPG from a fill-up (miles driven and fuel used), use the MPG Calculator; to cost a journey, use the Fuel Cost Calculator.

Frequently asked questions

30 US MPG is 7.84 L/100 km. 30 UK MPG is 9.42 L/100 km.

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