MPG to L/100km converter
Convert UK miles-per-gallon fuel economy figures to litres-per-100km, the unit used across most of Europe — useful for comparing UK and EU car specifications.
Result
Fuel economy
How to use this calculator
- Enter your car's fuel economy in mpg (UK gallons).
- Read the equivalent in litres per 100km.
Assumptions
- Uses UK gallons, not US gallons, which are smaller and would give a different result.
Technical details: what the fields mean
- Fuel economy
mpg - Miles per UK gallon (4.54609 litres) — the figure normally quoted on UK car specs.
Methodology
L/100km = (100 × 4.54609) ÷ (mpg × 1.609344). Note the relationship is inverse — higher mpg means lower L/100km.
Worked example
45 mpg
Inputs: mpg=45
Result: 6.28 L/100km
Practical guidance
- Useful when comparing a UK-spec car's mpg figure to a European review or spec sheet quoted in L/100km.
Common mistakes
- Confusing UK and US gallons — they differ by about 20%, which would give a noticeably wrong result.
FAQs
What is 45 mpg in L/100km?
About 6.28 L/100km.