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Fuel Economy Calculator (MPG, L/100km, km/L)

Fuel economy calculator — convert distance and fuel into US MPG, European L/100 km, and km/L.

Fuel Economy

Distance and fuel consumed

MPG25 mpg
L / 100 km9.4085833
km / L10.628593
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About this tool

Compute fuel economy from a measured distance and fuel consumed. Reports US MPG, European L/100 km, and km/L.

Formula

MPG = miles / gallons.   L/100km = 235.215 / MPG.   km/L = MPG · 0.4251.

Worked example

300 mi on 12 gal → 25 MPG ≈ 9.41 L/100 km ≈ 10.63 km/L.

Notes

L/100 km is inverted relative to MPG: lower is better. Going from 25 → 50 MPG saves more fuel per mile than going from 50 → 75 MPG.