Fuel Economy Converter
Convert US miles per gallon into liters per 100 km. These two units move in opposite directions: a higher mpg is a lower L/100 km. This page is not a fuel cost calculator.
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How to convert US mpg to L/100 km
- Enter the fuel economy as US miles per gallon. The default is 1 mpg.
- Keep From as Miles per gallon (US) and To as Liters per 100 km, or swap them.
- Read L/100 km. Divide 235.214583 by the mpg figure.
- Press Swap units to go from L/100 km back to US mpg. The value stays in this browser.
US miles per gallon
Fuel economy (harmonic with distance)
| US mpg | Miles driven per US gallon of fuel |
|---|---|
| L/100 km | Liters burned per 100 kilometers |
| Inverse pair | mpg = 235.214583 / (L/100 km) |
| Constant origin | 100 km / 1.609344 mi times 3.785411784 L per US gal |
| US gallon | 231 cubic inches, same as the volume converter |
| Not a cost | Price per liter or gallon lives on the fuel cost calculator |
What this fuel economy converter does
US miles per gallon (mpg) counts distance per volume. Liters per 100 km (L/100 km) counts volume per distance. They are reciprocals after a unit-system constant. This form starts at US mpg and targets L/100 km. A car that uses less fuel shows a larger mpg and a smaller L/100 km. You cannot add two mpg figures and divide by two if each stretch covers the same distance. Average L/100 km first, then convert, because L/100 km is linear with fuel for a fixed distance.
The US gallon here is 3.785411784 L, the same liquid gallon as liters to gallons. Trip spend belongs on the fuel cost calculator. The all-dimension list is the unit converter.
MPG and L/100 km formula
L/100 km = 235.214583 / mpg. mpg = 235.214583 / (L/100 km). The constant is (100 / 1.609344) × 3.785411784, which converts 100 km into miles and a US gallon into liters. Imperial (UK) gallons are not on this list. Zero and negative economy values are rejected because they do not describe a positive fuel rate.
Harmonic mpg versus L/100 km
If you drive 50 km at 8 L/100 km and 50 km at 12 L/100 km, the combined figure is 10 L/100 km. The mpg values of those two stretches do not average to the mpg of 10 L/100 km. That is why fleet and WLTP sheets prefer L/100 km or gallons per 100 miles. US window stickers still quote mpg. This page only converts one number. It does not mix city and highway cycles.
When to convert fuel economy here
Read a US mpg sticker as L/100 km, or turn a European spec into US mpg. Keep pump prices, tank volume, and trip distance on the fuel cost page. Keep liquid volume alone on volume.
What this page does not do
It does not multiply by a fuel price. It does not convert UK mpg (imperial gallon). It does not fetch live pump data. Input stays in this tab.