Convert MPG (UK) to Liters per 100km
MPG (UK) to liters per 100km is the conversion you need when a car's economy is quoted in imperial miles per gallon but you think in the metric measure of fuel used per distance. The two run in opposite directions: you divide 282.480936 by the MPG (UK) figure, so a higher MPG means a lower L/100km.
Miles per gallon (UK) to Liters per 100 km conversion table
| Miles per gallon (UK) (mpg (UK)) | Liters per 100 km (L/100km) |
|---|---|
| 1 | 282.480936 |
| 2 | 141.240468 |
| 3 | 94.160312 |
| 5 | 56.496187 |
| 10 | 28.248094 |
| 20 | 14.124047 |
| 50 | 5.649619 |
| 100 | 2.824809 |
| 500 | 0.564962 |
| 1,000 | 0.282481 |
The formula
To convert MPG (UK) to liters per 100km, divide 282.480936 by the imperial figure:
L/100km = 282.480936 ÷ MPG (UK)
A worked example
Say a car is rated at 40 MPG (UK) and you want L/100km:
282.480936 ÷ 40 = 7.06 L/100km
So 40 MPG (UK) is about 7.06 L/100km.
Why it's an approximation
MPG (UK) and L/100km are inverses. One measures how far you go on a set amount of fuel; the other measures how much fuel you burn over a set distance. To move between them you don't multiply — you divide 282.480936 by the MPG (UK) figure. That inverse relationship is why a higher MPG gives a lower L/100km: more miles per gallon means less fuel per 100 km. The constant 282.480936 is rounded, so the answer is close but stays approximate.
When you'll use it
Reading a UK car rating in the metric measure the rest of the world uses, comparing an imperial MPG figure against a car spec quoted in L/100km, or checking real fuel use per distance instead of distance per gallon.
Frequently asked questions
Why do you divide instead of multiply for L/100km?
Because MPG and L/100km are inverses of each other. MPG measures distance per fuel (more is better), while L/100km measures fuel per distance (less is better). To flip between them you divide 282.480936 by the MPG (UK) figure — so as MPG goes up, L/100km comes down.
How many L/100km is 40 MPG (UK)?
About 7.06 L/100km. Divide 282.480936 by 40 to get 7.06. Double the MPG and the L/100km roughly halves, because they're inverses.
Is the MPG (UK) to L/100km conversion exact?
No. The constant 282.480936 is rounded, and because the relationship is a division rather than a straight multiply, the result is approximate — precise enough for comparing cars, but not an exact figure.