Tools · MPG calculator
MPG Calculator
Convert fuel economy between MPG (US), MPG (imperial), L/100km, and km/L. Edit any one field and the other three update live. Includes a trip fuel cost calculator below.
1 US gal = 3.785411784 L · 1 imperial gal = 4.54609 L · 1 mile = 1.609344 km
Three ways to measure the same thing
Fuel economy is one number that goes by four different names depending on where you live. The United States uses MPG (US): how many miles you travel per US gallon. The UK uses MPG (imperial), which is the same idea but with the larger imperial gallon (about 20 percent bigger), so an imperial MPG figure is always about 20 percent higher than the US one for the same car. Most of the world uses L/100km: how many liters it takes to travel 100 km. Lower is better here, the opposite of MPG. Some countries also use km/L: kilometers traveled per liter, which behaves like MPG (higher is better).
A 30 MPG (US) car is a 36 MPG (imperial) car is a 7.84 L/100km car is a 12.75 km/L car. Same vehicle, same fuel burn, just different units. Use the converter above to go between them.
Trip fuel cost calculator
How much fuel will a trip use, and what will it cost? Enter the trip distance, current fuel economy, and fuel price.
Common fuel economy reference
| L/100km | MPG (US) | MPG (imp) | km/L |
|---|---|---|---|
| 3.50 | 12.15 | 10.11 | 28.57 |
| 4.50 | 9.45 | 7.87 | 22.22 |
| 5.50 | 7.73 | 6.44 | 18.18 |
| 6.50 | 6.54 | 5.45 | 15.38 |
| 7.50 | 5.67 | 4.72 | 13.33 |
| 8.50 | 5.00 | 4.16 | 11.76 |
| 10.00 | 4.25 | 3.54 | 10.00 |
| 12.00 | 3.54 | 2.95 | 8.33 |
| 15.00 | 2.83 | 2.36 | 6.67 |
Related tools
- Speed, distance, time calculator — for the time half of a road trip plan.
- MPH to KPH converter for the speed side.
- Live GPS speedometer — measure your actual speed.