MPG to L/100km converter
Type a fuel economy figure in any unit (US mpg, UK mpg, L/100km or km/L) and get the other three at once.
Formulas: L/100km = 235.215 ÷ US mpg = 282.481 ÷ UK mpg. UK mpg = US mpg × 1.20095.
MPG to L/100km conversion table
| US mpg | L/100km | UK mpg | km/L |
|---|---|---|---|
| 10 mpg | 23.52 | 12.0 | 4.25 |
| 12 mpg | 19.60 | 14.4 | 5.10 |
| 15 mpg | 15.68 | 18.0 | 6.38 |
| 18 mpg | 13.07 | 21.6 | 7.65 |
| 20 mpg | 11.76 | 24.0 | 8.50 |
| 22 mpg | 10.69 | 26.4 | 9.35 |
| 25 mpg | 9.41 | 30.0 | 10.63 |
| 28 mpg | 8.40 | 33.6 | 11.90 |
| 30 mpg | 7.84 | 36.0 | 12.75 |
| 32 mpg | 7.35 | 38.4 | 13.60 |
| 35 mpg | 6.72 | 42.0 | 14.88 |
| 40 mpg | 5.88 | 48.0 | 17.01 |
| 45 mpg | 5.23 | 54.0 | 19.13 |
| 50 mpg | 4.70 | 60.0 | 21.26 |
| 55 mpg | 4.28 | 66.1 | 23.38 |
| 60 mpg | 3.92 | 72.1 | 25.51 |
L/100km to MPG table
| L/100km | US mpg | UK mpg |
|---|---|---|
| 3 L/100km | 78.4 | 94.2 |
| 4 L/100km | 58.8 | 70.6 |
| 5 L/100km | 47.0 | 56.5 |
| 5.5 L/100km | 42.8 | 51.4 |
| 6 L/100km | 39.2 | 47.1 |
| 6.5 L/100km | 36.2 | 43.5 |
| 7 L/100km | 33.6 | 40.4 |
| 7.5 L/100km | 31.4 | 37.7 |
| 8 L/100km | 29.4 | 35.3 |
| 9 L/100km | 26.1 | 31.4 |
| 10 L/100km | 23.5 | 28.2 |
| 11 L/100km | 21.4 | 25.7 |
| 12 L/100km | 19.6 | 23.5 |
| 14 L/100km | 16.8 | 20.2 |
| 16 L/100km | 14.7 | 17.7 |
Single-value pages: 15 mpg · 20 mpg · 25 mpg · 30 mpg · 35 mpg · 40 mpg · 45 mpg · 50 mpg · 55 mpg · 60 mpg
The MPG illusion: which upgrade saves more fuel?
Quick: is swapping a 12 mpg truck for a 14 mpg one better or worse than swapping a 30 mpg sedan for a 40 mpg one? Most people pick the sedan, because +10 looks bigger than +2. Drag the sliders and watch the gallons.
Upgrade A
119 gallons saved per 10,000 miles (19.6 → 16.8 L/100km)
Upgrade B
83 gallons saved per 10,000 miles (7.8 → 5.9 L/100km)
With the defaults, the humble 12 → 14 mpg swap saves about 119 gallons and the 30 → 40 swap only 83. Fuel used is 1 ÷ MPG, a curve: gains at the low end matter far more. Researchers Richard Larrick and Jack Soll named this the "MPG illusion" (Science, 2008). It is one reason Europe and Canada rate cars in L/100km, which grows in a straight line with fuel burned.
Questions drivers ask
How do you convert MPG to L/100km?
Divide 235.215 by the US mpg figure. 25 mpg = 235.215 ÷ 25 = 9.41 L/100km. For UK (imperial) mpg divide 282.481 instead.
How do you convert L/100km to MPG?
It is the same number: 235.215 ÷ L/100km gives US mpg, and 282.481 ÷ L/100km gives UK mpg. 6 L/100km = 39.2 US mpg = 47.1 UK mpg.
Why is UK mpg higher than US mpg for the same car?
An imperial gallon is 4.546 litres while a US gallon is 3.785 litres, so a UK gallon takes you about 20% further. Multiply US mpg by 1.201 to get UK mpg.
Is lower L/100km better?
Yes. L/100km measures fuel used per distance, so lower is better. MPG measures distance per fuel, so higher is better.
How do I convert MPG to km/L?
Multiply US mpg by 0.4251 (or UK mpg by 0.354). 30 US mpg = 12.75 km/L.