Fuel Economy Calculator
Calculate MPG, L/100 km, km/L, and cost per mile or kilometer
Calculation Steps
How Fuel Economy Is Calculated
Use trip distance or odometer readings with fuel added at the pump.
MPG
Miles per gallon divides miles driven by gallons used. Higher MPG means better fuel economy.
L/100 km
Liters per 100 km divides liters used by kilometers driven, then multiplies by 100. Lower L/100 km means better economy.
Fill-up method
For the most practical measurement, fill the tank, record the odometer, drive, fill again, then enter the fuel added and odometer change.
Fuel Economy Examples
Quick examples for MPG, metric economy, and fill-up tracking.
Gas mileage
300 miles on 10 gallons equals 30 MPG
Metric economy
500 km on 32.5 liters equals 6.5 L/100 km
Fill-up reading
Use odometer mode when you know the start reading, end reading, and fuel added.
Fuel Economy Calculator FAQ
Common questions about MPG, L/100 km, odometer fill-ups, and real-world gas mileage.
How do I calculate MPG?
Divide miles driven by gallons used. For example, 300 miles on 10 gallons equals 30 MPG.
How do I calculate L/100 km?
Divide liters used by kilometers driven, then multiply by 100. Lower L/100 km means better fuel economy.
Should I use trip distance or odometer readings?
Use trip distance when you already know it. Use odometer mode after filling the tank, driving, then filling again to measure fuel used.
Why does real fuel economy change between fill-ups?
Traffic, tire pressure, speed, terrain, weather, cargo, fuel blend, and pump shutoff variation can all change measured fuel economy.
Is fuel price required?
No. Fuel price is optional. Enter it when you also want total fuel cost and cost per mile or kilometer.