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MPG to L/100 km

Miles per gallon (US) (mpg) to liters per 100 km (L/100 km).

Result7.84049L/100 km

Precision (significant figures)

Formula

L/100 km = 235.215 ÷ mpg

1 mpg = 235.215 L/100 km

L/100 km = 235.215 ÷ mpg (US). The two scales are inverses: more mpg means fewer liters per 100 km. So 30 mpg is 7.84049 L/100 km, 40 mpg is 5.88036 and 20 mpg is 11.7607. For UK mpg, divide 282.481 instead.

Formula

L/100 km = 235.215 ÷ mpg

Worked example

  1. Start with 30 mpg.
  2. Divide 235.215 by the value: 235.215 ÷ 30 = 7.84049 L/100 km.

Mpg to l/100km chart

Miles per gallon (US) (mpg)Liters per 100 km (L/100 km)
1023.5215
1515.681
2011.7607
2210.6916
259.40858
288.40052
307.84049
327.35046
356.72042
405.88036
455.22699
504.70429
554.27663
603.92024
753.13619
1002.35215

When you need this conversion

Comparing cars between the US, UK and metric markets, reading European or Australian reviews, and estimating trip fuel.

Quick reference (US mpg)

  • 20 mpg = 11.7607 L/100 km
  • 25 mpg = 9.40858 L/100 km
  • 30 mpg = 7.84049 L/100 km
  • 40 mpg = 5.88036 L/100 km
  • 50 mpg = 4.70429 L/100 km

Why the gains shrink

Going from 20 to 25 mpg saves 2.35 L/100 km; going from 40 to 50 mpg saves only 1.18 L/100 km. Liters per 100 km show real fuel savings more honestly, which is why the EPA label also shows gallons per 100 miles.

Common mistakes

Using UK mpg figures as US. A UK-rated 50 mpg is 41.6 US mpg.

Averaging mpg. To combine trips, add up the fuel and distance; don’t average the mpg figures.

For the reverse, use L/100 km to mpg.

Questions

What is 30 mpg in L/100 km?

7.84 L/100 km (US mpg), or 9.42 L/100 km for UK mpg.

What is 25 mpg in L/100 km?

9.40858 L/100 km.

Why can't I just multiply?

L/100 km measures fuel per distance; mpg measures distance per fuel. One is the reciprocal of the other, so the conversion divides a constant by the value.

Why do UK and US mpg differ?

A UK gallon (4.546 L) is 20% bigger than a US gallon (3.785 L), so the same car shows a higher UK mpg.

Sources

Last reviewed 2026-09-24. How we check values · Report a problem with this page

Further reading