⛽ Fuel Efficiency Converter
Convert between km/L, miles per gallon (US & UK), and L/100km for comparing fuel economy across standards.
Quick Reference
Understanding Fuel Efficiency Units
Different countries measure fuel efficiency differently. The US uses miles per gallon (MPG), most of Europe and Asia use litres per 100 km (L/100km), and some countries like India and Japan use km/L. Understanding these units is essential when comparing vehicles across markets.
Key Formulas
- km/L → L/100km: L/100km = 100 ÷ km/L
- km/L → MPG (US): MPG = km/L × 2.35215
- km/L → MPG (UK): MPG = km/L × 2.82481
- MPG (US) → km/L: km/L = MPG ÷ 2.35215
Common Equivalents
| km/L | MPG (US) | MPG (UK) | L/100km |
|---|---|---|---|
| 5 | 11.76 | 14.12 | 20.00 |
| 10 | 23.52 | 28.25 | 10.00 |
| 15 | 35.28 | 42.37 | 6.67 |
| 20 | 47.04 | 56.50 | 5.00 |
| 25 | 58.80 | 70.62 | 4.00 |
Note on L/100km
L/100km is an inverse unit — a lower number means better efficiency. A car getting 5 L/100km is more efficient than one getting 10 L/100km. This is opposite to km/L and MPG where higher is better.
Frequently Asked Questions
A UK (imperial) gallon is about 20% larger than a US gallon (4.546 L vs 3.785 L). So you travel more miles on one imperial gallon, making the UK MPG number higher for the same car.
For petrol cars, 15–20 km/L (35–47 MPG US) is considered good. Hybrids can achieve 20–30 km/L (47–70 MPG US). Diesel cars typically get 18–25 km/L. Electric vehicles are measured in kWh/100km instead.
Simply divide 100 by the L/100km value. For example, 8 L/100km = 100 ÷ 8 = 12.5 km/L. They have an inverse relationship.