Converter hub
Fuel Economy Converter
Fuel economy is the only category with inverse units: litres per 100 km falls as efficiency rises, while miles per gallon rises. The conversion is therefore a division, not a multiplication. Pick a pair below or open the page for the exact factor, a worked example and a full chart.
Units in this category
Fuel economy is the only category with inverse units: litres per 100 km falls as efficiency rises, while miles per gallon rises. The conversion is therefore a division, not a multiplication.
| Unit | Symbol | Definition |
|---|---|---|
| Kilometers per Liter | km/L | Kilometres per litre is a direct fuel-economy measure used in many markets. |
| Miles per Gallon (US) | mpg | US miles per gallon equals about 0.425 km/L; the UK gallon is larger. |
| Miles per Gallon (UK) | mpg (UK) | UK miles per gallon equals about 0.354 km/L because the imperial gallon is 4.546 litres. |
| Liters per 100km | L/100km | Litres per 100 km is an inverse measure: lower is better, and it is not linear. |
All fuel economy conversions
Every listed pair has its own page with the formula, examples and a chart. Choose the starting unit:
Kilometers per Liter (km/L)
Miles per Gallon (US) (mpg)
Miles per Gallon (UK) (mpg (UK))
Liters per 100km (L/100km)
Frequently asked questions
How many fuel economy units are supported?
4 units, which gives 8 one-way conversions.
Are the factors exact?
They follow SI and international definitions. Where a unit is approximate by nature (for example Mach, months or fuel economy), the page says so.
Can I convert in both directions?
Yes. Every pair page has a swap link and the calculator accepts any decimal value.