Understanding your calculation
Method, example and limitations
How the calculation works
Fuel economy divides distance by fuel used for miles per gallon or kilometers per liter. Liters per 100 km instead divides fuel by distance and multiplies by 100.
Example to check
Traveling 300 miles using 10 US gallons gives 30 MPG. Traveling 500 km using 30 L gives 6 L/100 km.
Before using the result
US and imperial gallons differ. Refill consistently when measuring consumption; a single short trip can give an unreliable average.