Global Fuel CalculatorUK MPG to US MPG Converter
A British review says a hatchback manages 50 MPG, while an American listing for the same car says 41-something. Neither is wrong. This converter takes a UK (imperial) MPG figure and shows what it is in US gallons, so you can compare like with like before deciding which car is really the thirstier one.
Because the US gallon is smaller, the US number comes out lower, about 17% lower than the UK one. The result also lists L/100km and km/L, which don't depend on any gallon at all and make a neutral way to compare cars from different markets.
UK MPG to US MPG Converter
The conversion formula
US MPG = UK MPG ÷ 1.20095
Worked example: 40 MPG (imp) = 33.31 MPG (US)
Need it the other way round? Use the US MPG to UK MPG Converter.
UK MPG to US MPG conversion table
| MPG (imp) | L/100km | km/L | MPG (US) |
|---|---|---|---|
| 30 | 9.42 | 10.62 | 24.98 |
| 35 | 8.07 | 12.39 | 29.14 |
| 40 | 7.06 | 14.16 | 33.31 |
| 45 | 6.28 | 15.93 | 37.47 |
| 50 | 5.65 | 17.70 | 41.63 |
| 55 | 5.14 | 19.47 | 45.80 |
| 60 | 4.71 | 21.24 | 49.96 |
How to use the UK MPG to US MPG Converter
- Enter your value. Type the figure you want to convert, in MPG (imperial).
- Check the units. Make sure "From" shows MPG (imperial) and "To" shows MPG (US). Press Swap to reverse them.
- Read the result. The answer appears straight away, worked out as US MPG = UK MPG ÷ 1.20095.
- Check common values. Compare against the conversion table below if you want to sanity-check a figure.
Common questions
How do I convert UK MPG to US MPG?
Divide the UK figure by 1.2009, or multiply it by 0.8327. Forty UK MPG is about 33.31 US MPG, and 50 UK MPG is about 41.63 US MPG.
Why does the same car show a lower MPG in American listings?
US listings count miles per US gallon, which is a smaller volume (3.785 litres against 4.546). Fewer litres per gallon means fewer miles per gallon, even though the car burns exactly the same fuel.
What counts as a good UK MPG figure?
The mid-40s is fairly typical for a modern petrol hatchback, and anything above 60 usually points to a diesel or a hybrid. In US terms those are roughly 37 and 50.
Can I trust this for a figure I measured myself?
Yes. The conversion only changes the unit. It works the same for a brochure rating and for the number you work out at your own fill-up.
Why not just use L/100km?
You can, and it is the cleanest option because it has no gallon in it. But UK drivers and car magazines still think in MPG, which is why a reliable converter is handy.