Measure real-world fuel economy and convert between common efficiency units.
Overview
The Gas Mileage Calculator helps you track actual vehicle efficiency using odometer distance and fuel consumed.
It can convert results across MPG, km/L, and L/100km so you can compare efficiency in any preferred unit.
Log multiple fill-ups over time to smooth out pump-to-pump variation and detect real MPG changes in vehicle performance.
Steps
Use trip meter or odometer difference for accuracy.
Input gallons or liters filled for that distance.
Select MPG, km/L, or L/100km.
Generate fuel economy value for the period.
Repeat entries to monitor long-term efficiency changes.
Math
MPG = miles / gallons; L/100km = (liters / km) x 100
Efficiency is distance per fuel unit, while L/100km expresses fuel consumed per fixed 100-km distance.
Worked cases
420 / 14
30 MPG
600 / 40
15 km/L
(40 / 600) x 100
6.67 L/100km
Why use this
Questions