Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Convert US miles-per-gallon fuel economy to liters per 100 kilometers.
US fuel economy is measured in miles per gallon (MPG), while most other countries use liters per 100 kilometers (L/100km) -- a different, inverted unit (lower is better in L/100km, unlike MPG where higher is better). This tool converts between them using L/100km = 235.214583 ÷ MPG.
Enter your vehicle's US MPG rating. The equivalent L/100km figure appears instantly.
MPG measures distance per unit of fuel, while L/100km measures fuel per unit of distance. They are reciprocals of each other, scaled by unit conversions between US gallons and liters and between miles and kilometers. That is why the tool divides a constant, 235.214583, by the MPG value instead of multiplying by a fixed factor. The same constant works in both directions: dividing it by an L/100km figure gives US MPG.
L/100km = 235.214583 / MPG (US gallons); MPG = 235.214583 / L/100km
A car rated at 28 US MPG converts to 235.214583 / 28, about 8.40 L/100km. A vehicle at 35 MPG is about 6.72 L/100km, and one at 20 MPG is about 11.76 L/100km. Notice that the relationship is not linear. Going from 20 to 25 MPG (a gain of 5) reduces consumption by about 2.35 L/100km, while going from 40 to 45 MPG (also a gain of 5) reduces it by only about 0.58 L/100km. This is why economists and engineers often prefer to measure fuel per distance: improvements at the low-MPG end save far more fuel than the same MPG gain at the high end.
This tool is for US MPG. The UK and some other countries use the imperial gallon, which is larger than the US gallon, so the same car has a higher MPG figure in imperial units. If you are comparing a UK MPG rating to a US MPG rating, do not use this converter on the imperial number directly, since the result would be wrong. Convert the imperial figure to US MPG first, or find the vehicle's official L/100km rating.
Remember that lower is better with L/100km. A car at 6 L/100km is more efficient than one at 9. When you are choosing between two vehicles, the difference in liters per 100 km directly shows how much more fuel one uses over the same distance. For instance, a 2 L/100km gap over 15,000 km is about 300 liters per year, which you can multiply by a local fuel price to estimate the annual difference.
L/100km measures fuel consumed per fixed distance, so less fuel used means a lower (better) number -- the opposite direction from MPG, which measures distance per fixed fuel amount, where more distance means a higher (better) number.
Divide 235.214583 by the L/100km figure. For example, 8 L/100km is about 29.4 US MPG.
US gallons. Imperial MPG figures used in the UK give different results and need to be converted to US MPG first.
Because MPG and L/100km are reciprocals. The same MPG gain saves more fuel per distance when starting from a low MPG than from a high one.
No. Electric vehicles are rated in energy use, such as kWh per 100 km, or an MPG-equivalent that follows different rules. This tool is designed for liquid fuel.
Reference: EPA Fuel Economy