Fuel economy is either distance per fuel (mpg, km/L: higher is better) or fuel per distance (L/100km: lower is better). The conversion is L/100km = 235.215 ÷ MPG (US), or 282.481 ÷ MPG (UK). The UK gallon is larger (4.546 L vs 3.785 L), so the same car has a higher UK mpg figure.
| MPG (US) | L/100km | km/L |
|---|
Divide 235.215 by the US mpg figure. 30 mpg = 235.215 ÷ 30 = 7.84 L/100km. For UK mpg, divide 282.481 instead.
The same formula works in reverse: 235.215 ÷ L/100km gives US mpg. 8 L/100km = 29.4 mpg (US).
30 mpg (US) is about 7.8 L/100km, a fairly typical figure for a modern petrol car. Hybrids often reach 45–55 mpg (4.3–5.2 L/100km).
The gallons differ. One imperial (UK) gallon is 4.546 litres and one US gallon is 3.785 litres, so 1 UK mpg is about 0.833 US mpg.
No, everything is calculated in your browser.
See also: Gallons to Liters · Miles to Km · Km to Miles