Fuel Efficiency
MPG ↔ L/100km
About This Calculator
Fuel efficiency measures how far a vehicle travels per unit of fuel. The US uses miles per gallon (MPG) where higher is better; most other countries use liters per 100 km (L/100km) where lower is better. Converting between them requires division rather than multiplication.
Formula
L/100km = 235.215 / MPG
MPG = 235.215 / (L/100km)
km/L = 100 / (L/100km)
Example Calculation
Convert 35 MPG to L/100km.
- L/100km = 235.215 / 35 = 6.72 L/100km
35 MPG = 6.72 L/100km
MPG to L/100km Conversion Table
| MPG | L/100km |
|---|---|
| 15 | 15.68 |
| 20 | 11.76 |
| 25 | 9.41 |
| 30 | 7.84 |
| 35 | 6.72 |
| 40 | 5.88 |
| 45 | 5.23 |
| 50 | 4.70 |
Frequently Asked Questions
Why is L/100km the opposite of MPG?
MPG expresses distance per unit of fuel (higher is better), while L/100km expresses fuel used per unit of distance (lower is better). This means they have an inverse relationship: you must divide to convert between them.
What is good fuel economy for a car?
For a gasoline car, 30+ MPG (under 7.8 L/100km) is considered good. Hybrid cars often achieve 45-55 MPG. Electric vehicles are rated in MPGe (miles per gallon equivalent), typically 100+ MPGe.
What is the difference between US MPG and UK MPG?
The UK uses imperial gallons (4.546 L), while the US uses US gallons (3.785 L). A UK MPG figure is about 20% higher than the US MPG for the same vehicle. Always check which gallon standard is being used.