I'm leasing a car in the UK rated 48 mpg. My company's European fleet policy requires cars under 120g CO2/km and 6 L/100km. Does it qualify?

282.481 ÷ 48 = 5.88 L/100km. Yes — just under the 6 L/100km limit. Note that real-world consumption may differ from the official WLTP test figure, so check the CO2 certification separately.

Why does the UK still use mpg instead of switching to L/100km like the rest of Europe?

mpg (Imperial) is deeply embedded in UK driving culture and consumer expectation. Despite metrication in most areas, fuel economy regulations and consumer testing bodies (like What Car?) continue to publish in mpg. The EU required L/100km labelling, but Brexit means the UK is no longer bound by that requirement.

A US friend says his car gets 30 mpg. My UK car gets 30 mpg too. Are they the same?

No — your UK car is actually more efficient. 30 mpg (US) = 282.481 ÷ (30 × 1.20095) = 7.84 L/100km, while your 30 mpg (Imperial) = 282.481 ÷ 30 = 9.42 L/100km. Wait — that means your car uses more fuel. The US gallon is smaller, so 30 mpg (US) actually takes you further per liter. See: [mpg (Imperial) to mpg (US)](/fuel/mpg-imperial-to-mpg/).

Is there a quick estimate I can do in my head?

A rough rule: divide 280 by mpg (Imperial) to get approximate L/100km. For example, 40 mpg → 280 ÷ 40 = 7 L/100km (actual: 7.06). Accurate enough for everyday comparisons.

MPG (Imperial) to Liters per 100km Converter

Enter a value to instantly convert between fuel economy units.

From

Precision4 dp

1 MPG (Imperial) = 282.4809 Liters per 100km

Key Formulas

MPG (US) → Liters per 100km

L/100km = mpg × 235.215

Liters per 100km → MPG (US)

mpg = L/100km × 235.215

Km per Liter → MPG (US)

mpg = km/L × 2.35215

MPG (US) → Km per Liter

km/L = mpg × 0.425144

Formula

L/100km = 282.481 ÷ mpg (Imperial)

Bought a car in the UK and want to compare its fuel economy to European or Australian specs? The UK measures efficiency in miles per Imperial gallon, while Europe uses liters per 100 kilometers. The Imperial gallon holds 4.546 liters — about 20% more than the US gallon — so UK mpg figures are always higher than US mpg for the same vehicle. When you see a UK car claiming 50 mpg and a European equivalent claiming 5.8 L/100km, you need this conversion to confirm they're describing the same level of efficiency (they are: 282.481 ÷ 50 = 5.65 L/100km, very close).

Source: NIST SP 811, Table B.8

Frequently Asked Questions

Real-World Examples

A popular UK turbodiesel rated 50 mpg (Imperial) converts to 5.65 L/100km — impressive by European WLTP standards too.

50 mpg imp = 5.65 L/100km

A UK family saloon at 35 mpg (Imperial) uses 8.1 L/100km, slightly above the European average for this class.

35 mpg imp = 8.07 L/100km

A small UK petrol hybrid at 60 mpg (Imperial) achieves 4.7 L/100km — among the most efficient non-EV ratings on the European market.

60 mpg imp = 4.71 L/100km

A large UK SUV at 25 mpg (Imperial) consumes 11.3 L/100km, typical for petrol 4WD vehicles and considered heavy by European standards.

25 mpg imp = 11.3 L/100km

mpg to l per 100km l per 100km to mpg kml to mpg mpg to kml

MPG (Imperial) to Liters per 100km Converter

Key Formulas

Formula

Frequently Asked Questions

Real-World Examples

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