How this calculator works
Litres per 100 kilometres measures consumption: lower is better. Miles per gallon measures distance travelled per fuel volume: higher is better. A direct conversion must therefore take the reciprocal, not just multiply by a constant.
For example, 45 UK MPG is approximately 6.28 L/100 km, while 45 US MPG is approximately 5.23 L/100 km. The numbers are not equivalent because the gallon sizes are different.
Reference: Official guidance / methodology. External rates can change.
Common questions
Which MPG do British car dashboards use?
UK manufacturers and UK motoring information commonly use imperial MPG. Some imported manuals and online listings use US gallons; check the source.
Can I convert km/L to MPG?
Yes. Choose km/L as the input unit, enter the figure and the calculator gives the equivalent UK and US MPG.