Fuel Economy Converter

Use this free fuel economy converter to instantly convert between miles per gallon (MPG), liters per 100 kilometers (L/100km), kilometers per liter (km/L), and miles per liter. Enter any value and all units update automatically.

How to use this Fuel Economy Converter

Enter a fuel economy value in any field and all other units update automatically. Type a value in MPG to instantly see the equivalent in liters per 100 kilometers, kilometers per liter, and miles per liter. Type in any field and all others convert at the same time. Note that MPG, km/L, and mi/L are efficiency ratings where higher is better, while L/100km is a consumption rating where lower means the car uses less fuel per distance traveled.

Frequently asked questions

Q: How do I convert MPG to L/100km?
A: Divide 235.215 by the MPG value to get L/100km. For example, 30 MPG = 235.215 ÷ 30 = 7.84 L/100km. To go the other direction, divide 235.215 by the L/100km value to get MPG. Note that because L/100km is an inverse measurement, higher MPG always corresponds to lower L/100km.

Q: What is considered good fuel economy?
A: In the United States, the EPA considers any vehicle rated above 30 MPG combined to be fuel-efficient. Hybrid vehicles typically achieve 40 to 55 MPG. In Europe, a fuel-efficient car typically consumes 5 to 6 liters per 100 kilometers. A very efficient diesel vehicle in Europe may achieve 4 L/100km or less.

Q: Why does Europe use L/100km instead of MPG?
A: L/100km expresses how much fuel a vehicle consumes to travel a fixed distance, which many argue is more intuitive for calculating actual fuel costs. MPG expresses how far a vehicle can travel on a fixed amount of fuel. Both measure the same thing from different perspectives. Most of the world uses L/100km while the United States, United Kingdom, and a few other countries use MPG.

Q: How does fuel economy change at highway vs city speeds?
A: Most gasoline vehicles achieve better fuel economy at steady highway speeds around 50 to 65 mph than in city driving due to constant acceleration and braking in stop-and-go traffic. EPA fuel economy ratings list separate city and highway figures for this reason. Hybrid vehicles often perform better in city driving because they recover braking energy.

Q: How much money can I save by switching to a more fuel-efficient vehicle?
A: A rough calculation: annual fuel cost = (miles driven ÷ MPG) × price per gallon. For example, driving 15,000 miles per year at $3.50/gallon in a 25 MPG car costs $2,100/year. Switching to a 35 MPG car saves $600/year. The US Department of Energy's fueleconomy.gov provides a detailed comparison tool for specific vehicles.