Fuel Consumption Unit Conversion: How to Convert L/100km and MPG
Fuel consumption is one of the most confusing areas of unit conversion because different countries use inverse metrics. In Europe and most of the world, fuel consumption is measured in liters per 100 kilometers (L/100km), where lower is better. In the US and UK, it's measured in miles per gallon (MPG), where higher is better.
The Two Systems
L/100km (Liters per 100km): Used in Europe, Canada, Australia, China, Japan, Korea. Lower is better. Typical range: 3-15 L/100km. A Toyota Prius gets about 4.5 L/100km; a large SUV might get 12 L/100km.
MPG (Miles per Gallon): Used in US and UK. Higher is better. Typical range: 15-50 MPG. The same Prius gets about 52 MPG (US).
Critical: US vs UK Gallons
US MPG and UK MPG are different because the gallons differ:
Conversion Formulas
Quick Reference
Real Cars
Trip Cost Calculation
L/100km method: (Distance Γ Consumption) Γ· 100 Γ Fuel Price
Example: 500 km Γ 8 L/100km = 40 L Γ $1.50/L = $60
MPG method: Distance Γ· MPG Γ Fuel Price per gallon
Example: 300 miles Γ· 30 MPG = 10 gal Γ $4.00 = $40
Tips
Use our Fuel Consumption Converter to convert between L/100km and MPG instantly.
| L/100km | US MPG | UK MPG | Rating |
|---|
| 3 | 78.4 | 94.2 | Excellent (hybrid) |
|---|---|---|---|
| 5 | 47.0 | 56.5 | Very good |
| 7 | 33.6 | 40.4 | Average |
| 10 | 23.5 | 28.2 | Poor (large SUV) |
| 15 | 15.7 | 18.8 | Very thirsty |