Fuel Economy Converter

Convert between MPG (US & UK), km/L, and L/100km instantly. Supports both efficiency (higher = better) and consumption (lower = better) units.

Value

From

Common Fuel Economy Conversions

MPG (US)	MPG (UK)	km/L	L/100km
20	24.02	8.50	11.76
25	30.03	10.63	9.41
30	36.03	12.75	7.84
35	42.04	14.88	6.72
40	48.04	17.01	5.88
50	60.05	21.26	4.71

Frequently Asked Questions

US MPG uses the US gallon (3.785 L), while UK MPG uses the Imperial gallon (4.546 L). Since the Imperial gallon is about 20% larger, the same car gets ~20% more UK MPG than US MPG. A car rated at 30 US MPG is approximately 36 UK MPG. Always check which gallon a fuel economy rating uses.

L/100km is a consumption metric (lower = more efficient), while MPG and km/L are efficiency metrics (higher = more efficient). They have an inverse relationship: L/100km = 100 ÷ km/L. A car using 5 L/100km is more efficient than one using 8 L/100km.

To convert US MPG to L/100km: divide 235.215 by the MPG value. For UK MPG divide 282.481 by the value. For example, 30 US MPG = 235.215/30 ≈ 7.84 L/100km. To go the other way, divide those constants by the L/100km value to get MPG.

L/100km: EU countries, Canada, Australia, South Africa. km/L: Japan, India, Korea, parts of Asia. US MPG: United States. UK MPG: United Kingdom (though L/100km is also displayed). The EU mandates CO₂ g/km alongside fuel economy figures on new cars.

How It Works

Enter Economy

Enter any fuel economy value. The converter handles the inverse relationship of L/100km automatically.

Pick Units

Choose from US MPG, UK MPG, km/L, and L/100km — covering all major fuel economy standards worldwide.

Instant Result

Results are shown immediately. The reference table lists typical efficiency values across all four units for easy comparison.

Common Use Cases

Car Shopping

Compare fuel economy of cars from different countries by converting between MPG (US/UK), km/L, and L/100km.

International Travel

Understand rental car fuel economy ratings when driving abroad — convert between local fuel economy units and what you're used to at home.

Fuel Cost Planning

Convert fuel economy to estimate trip fuel costs and compare fuel efficiency of different vehicles before a long journey.

Eco Comparisons

Compare environmental footprints of different vehicles across international standards to make greener choices.

Fleet Management

Convert and standardize fuel economy data from international fleets into a single unit for reporting and benchmark comparisons.

Automotive Journalism

Convert fuel economy figures cited in international press reviews to local units for your readership or publication's preferred format.

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