⛽ Fuel Consumption Converter
Fuel economy speaks different languages on every continent. This converter handles MPG (US), MPG (UK), km per liter, and the European L/100km where LESS is BETTER — the inverse relationship trips up a lot of people.
Last updated — all conversions use exact ISO 80000 unit definitions.
How fuel consumption works
Fuel economy has two opposite conventions. MPG-style measures distance per fuel — higher is better. L/100km measures fuel per distance — lower is better. They are mathematical reciprocals, so doubling your MPG halves your L/100km figure. The US gallon is 3.785 L but the UK imperial gallon is 4.546 L — that's why UK MPG numbers are always higher than US MPG for the same car.
Fuel economy reference
| Vehicle type | US MPG | L/100km |
|---|---|---|
| Small gasoline car | 35-40 | 5.9-6.7 |
| Mid-size sedan | 28-32 | 7.4-8.4 |
| Full-size SUV | 18-22 | 10.7-13.1 |
| Hybrid compact | 45-55 | 4.3-5.2 |
| Diesel van | 22-28 | 8.4-10.7 |
| Electric (equivalent) | 100+ | ~2.4 L equivalent |
Frequently asked questions
Why does L/100km go down when MPG goes up?
They are inverse measures. MPG = distance divided by fuel. L/100km = fuel divided by distance. One is literally the reciprocal of the other (with unit conversions). Better fuel economy means higher MPG but lower L/100km.
US gallon vs UK gallon — what's the difference?
A US gallon is 3.785 liters. A UK imperial gallon is 4.546 liters — about 20% larger. That's why a UK-gallon MPG figure is higher than a US-gallon MPG for the same actual fuel economy.
What is a good fuel economy?
Below 6 L/100km (above 39 US MPG) is excellent. 6-8 L/100km is typical for modern sedans. Above 10 L/100km (below 24 MPG) is gas-guzzler territory. Electric vehicles use kWh/100km instead — roughly 6-8 kWh/100km is equivalent to about 29-39 L/100km gasoline.
Estimates are for general information only — see our disclaimer.