Converter category
Fuel Economy Converter
Convert between MPG (US), MPG (UK), L/100km, km/L, mL/100mi, and US gallons per 100 miles for vehicle fuel efficiency.
Universal Fuel Economy Converter
About fuel economy conversions
Fuel economy conversions help you compare vehicle efficiency across different countries and measurement systems. Our fuel economy converter covers US miles per gallon, UK miles per gallon, liters per 100 kilometers, kilometers per liter, US gallons per 100 miles, and milliliters per 100 miles. Whether you are buying a car, comparing MPG and L/100km, analyzing fleet efficiency, or estimating fuel costs, this converter provides accurate conversions based on the exact relationships between US and UK gallons, miles, and kilometers.
Most popular fuel economy conversions
Available units
Popular fuel economy conversions (7 total)
Unit definitions
Miles per Gallon (US) (mpg)
MPG measures fuel efficiency - miles driven per gallon of fuel. Higher is better.
Origin: Standard US fuel economy metric.
Current use: Vehicle fuel economy (US), Car comparisons, Emissions standards
Miles per Gallon (UK) (mpg (UK))
Imperial MPG uses UK gallon (4.55L) vs US gallon (3.79L). About 20% higher than US mpg.
Origin: UK uses larger imperial gallon.
Current use: UK fuel economy, European vehicles, UK reporting
Liters per 100 km (L/100km)
European fuel efficiency measure. Lower is better - 5L/100km = 47 mpg.
Origin: Standard in Europe and Canada.
Current use: European fuel economy, Car comparisons, CO2 emissions
Kilometers per Liter (km/L)
Fuel efficiency in some Asian countries. Higher is better.
Origin: Used in Japan and other Asian markets.
Current use: Asian fuel economy, Vehicle specs, Efficiency reporting
Milliliters per 100 Miles (mL/100mi)
Very small fuel consumption measure, used for ultra-efficient vehicles.
Origin: Used for electric and hybrid vehicles.
Current use: Electric vehicles, Hybrid cars, Fuel economy research
US Gallons per 100 Miles (gal/100mi)
Fuel consumption measure where lower is better. Inverse of MPG.
Origin: Alternative to MPG for US reporting.
Current use: Fuel economy reporting, US standards, Fleet efficiency
Common uses for fuel economy conversions
Fuel economy conversions are used for car shopping, vehicle comparison, fleet management, emissions estimates, trip cost planning, and international travel.
Frequently asked questions about fuel economy
How do you convert MPG to L/100km?+
Divide 235.215 by the MPG value. For example, 30 mpg equals about 7.84 L/100km.
Why are US and UK MPG different?+
A US gallon is 3.785 liters, while a UK gallon is 4.546 liters. The same vehicle shows a higher MPG number in the UK because the gallon is larger.
Which fuel economy units does this converter support?+
It supports US mpg, UK mpg, L/100km, km/L, US gallons per 100 miles, and milliliters per 100 miles.