Fuel Efficiency Conversions
Convert fuel economy — MPG, L/100km, km/L. Free calculators for comparing cars across US and metric fuel labels.
5 units · 7 calculators · reference page (not prioritized for search)
Fuel efficiency can be expressed as distance per volume (miles per gallon, km per liter) or volume per distance (liters per 100 km). US labels use MPG; Europe and Canada often use L/100km — and higher MPG is better while lower L/100km is better, which confuses direct comparison.
These units are reciprocal relationships, not simple multipliers. Our calculators apply standard conversion formulas so you can compare a 35 MPG US vehicle with a 6.7 L/100km European rating fairly.
Quick fuel efficiency calculator
Fuel Efficiency Calculator
Popular fuel efficiency conversions
- Miles per Gallon (US) to Liters per 100 Kilometers (utility)
- Liters per 100 Kilometers to Miles per Gallon (US) (utility)
- Miles per Gallon (US) to Miles per Gallon (Imperial) (utility)
- Miles per Gallon (Imperial) to Miles per Gallon (US) (utility)
- Kilometers per Liter to Miles per Gallon (US) (utility)
- Miles per Gallon (US) to Kilometers per Liter (utility)
- Liters per 100 Kilometers to Kilometers per Liter (utility)
Real-world example
A rental car in Europe is listed at 5.5 L/100km and you want the US MPG equivalent. Converting gives roughly 43 MPG — useful when choosing the most economical option.
All fuel efficiency conversions
- Miles per Gallon (US) → Liters per 100 Kilometers
- Liters per 100 Kilometers → Miles per Gallon (US)
- Miles per Gallon (US) → Miles per Gallon (Imperial)
- Miles per Gallon (Imperial) → Miles per Gallon (US)
- Kilometers per Liter → Miles per Gallon (US)
- Miles per Gallon (US) → Kilometers per Liter
- Liters per 100 Kilometers → Kilometers per Liter
Fuel Efficiency units explained
- Miles per Gallon (US) (mpg) · base unit
- Also: mpg, miles per gallon, us mpg
- Miles per Gallon (Imperial) (mpg (Imp))
- Also: imperial mpg, uk mpg
- Liters per 100 Kilometers (L/100km)
- Also: liters per 100km, l/100km
- Kilometers per Liter (km/L)
- Also: kilometers per liter, km/l
- Miles per Liter (mi/L)
- Also: miles per liter
Frequently asked questions
- How do I convert MPG to L/100km?
- Use the formula L/100km = 235.214583 / MPG (US). Example: 30 MPG ≈ 7.84 L/100km.
- Why is lower L/100km better but higher MPG better?
- L/100km measures fuel used per distance (lower is better). MPG measures distance per fuel (higher is better). They are inverse measures.