Fuel economy converter
Type a figure in any box to convert between US mpg, UK mpg, litres per 100 km and kilometres per litre.
The formulas
l/100 km = 235.21 ÷ mpg (US), l/100 km = 282.48 ÷ mpg (UK) and km/l = 100 ÷ l/100 km. The US and Canada (for older cars) use mpg, the UK uses mpg with a bigger gallon, most of the world uses l/100 km, and India, Japan and much of Asia use km/l.
mpg to l/100 km table
| mpg | l/100 km (US mpg) | l/100 km (UK mpg) | km/l (US mpg) |
|---|---|---|---|
| 10 mpg | 23.5 | 28.2 | 4.3 |
| 15 mpg | 15.7 | 18.8 | 6.4 |
| 20 mpg | 11.8 | 14.1 | 8.5 |
| 25 mpg | 9.4 | 11.3 | 10.6 |
| 30 mpg | 7.8 | 9.4 | 12.8 |
| 35 mpg | 6.7 | 8.1 | 14.9 |
| 40 mpg | 5.9 | 7.1 | 17 |
| 45 mpg | 5.2 | 6.3 | 19.1 |
| 50 mpg | 4.7 | 5.6 | 21.3 |
| 60 mpg | 3.9 | 4.7 | 25.5 |
l/100 km to mpg table
| l/100 km | mpg (US) | mpg (UK) | km/l |
|---|---|---|---|
| 3 l/100 km | 78.4 | 94.2 | 33.3 |
| 4 l/100 km | 58.8 | 70.6 | 25 |
| 4.5 l/100 km | 52.3 | 62.8 | 22.2 |
| 5 l/100 km | 47 | 56.5 | 20 |
| 5.5 l/100 km | 42.8 | 51.4 | 18.2 |
| 6 l/100 km | 39.2 | 47.1 | 16.7 |
| 7 l/100 km | 33.6 | 40.4 | 14.3 |
| 8 l/100 km | 29.4 | 35.3 | 12.5 |
| 9 l/100 km | 26.1 | 31.4 | 11.1 |
| 10 l/100 km | 23.5 | 28.2 | 10 |
| 12 l/100 km | 19.6 | 23.5 | 8.3 |
| 15 l/100 km | 15.7 | 18.8 | 6.7 |
Real cars in every unit
The most economical petrol, diesel or hybrid version of each car registered in Europe in 2025 (official WLTP figures).
| Car | l/100 km | km/l | mpg (US) | mpg (UK) |
|---|---|---|---|---|
| Toyota Yaris 1.5 petrol | 4 | 25 | 58.8 | 70.6 |
| Renault Clio 1.8 petrol | 4 | 25 | 58.8 | 70.6 |
| Volkswagen Golf 2.0 diesel | 4.4 | 22.7 | 53.5 | 64.2 |
| Toyota Corolla 1.8 petrol | 4.7 | 21.3 | 50 | 60.1 |
| Hyundai Tucson 1.6 diesel | 5.3 | 18.9 | 44.4 | 53.3 |
| Toyota RAV4 2.5 petrol | 5.7 | 17.5 | 41.3 | 49.6 |
| BMW 3 Series 2.0 diesel | 5.2 | 19.2 | 45.2 | 54.3 |
| Ford Ranger 2.3 petrol hybrid | 3.7 | 27 | 63.6 | 76.3 |
| Toyota Hilux 2.4 diesel | 9.9 | 10.1 | 23.8 | 28.5 |
Questions
How do I convert mpg to l/100 km?
Divide 235.21 by the US mpg figure. 30 mpg (US) is 235.21 ÷ 30 = 7.8 l/100 km. For UK mpg, divide 282.48 instead.
How do I convert l/100 km to mpg?
Divide 235.21 by the l/100 km figure for US mpg, or 282.48 for UK mpg. A car using 6 l/100 km does 39.2 mpg (US) or 47.1 mpg (UK).
Why are UK and US mpg different?
A UK (imperial) gallon is 4.546 litres and a US gallon is 3.785 litres, so the same car shows about 20% more mpg in the UK. Always check which gallon a figure uses.
How do I convert km/l to l/100 km?
Divide 100 by the km/l figure. 20 km/l, a figure common in India, is 100 ÷ 20 = 5 l/100 km, which is 47 mpg (US).
Why is higher better for mpg but lower better for l/100 km?
mpg measures distance per fuel (how far you get), while l/100 km measures fuel per distance (how much you burn). They are reciprocals, which is also why the conversion isn't a simple multiplication.
Are official figures what I'll actually get?
Usually not exactly. Europe uses the WLTP test and the US uses EPA ratings, and real driving typically uses 10–25% more fuel depending on speed, temperature and load.