L/100km to MPG (UK) Converter
Convert litres per 100 km (L/100km) to Imperial miles per gallon (MPG UK). Formula: MPG (UK) = 282.481 ÷ L/100km.
How to Convert L/100km to MPG (UK)
The conversion is inverse: since L/100km measures fuel per distance and MPG measures distance per fuel, the formula is a division.
- MPG (UK) = 282.48094 ÷ L/100km
The constant 282.48094 = 100 × 4.54609 L ÷ 1.609344 km, based on exact NIST / ISO definitions of the Imperial gallon and mile.
L/100km ↔ MPG (UK) Reference Table
Common fuel-economy values expressed in all four units. Click any L/100km value for a dedicated conversion page.
| L/100km | MPG (UK) | MPG (US) | km/L | Category |
|---|---|---|---|---|
| 4 | 70.6 | 58.8 | 25.0 | Excellent |
| 5 | 56.5 | 47.0 | 20.0 | Very good |
| 6 | 47.1 | 39.2 | 16.7 | Good |
| 7 | 40.4 | 33.6 | 14.3 | Good |
| 8 | 35.3 | 29.4 | 12.5 | Average |
| 10 | 28.2 | 23.5 | 10.0 | Below average |
| 12 | 23.5 | 19.6 | 8.33 | Below average |
| 15 | 18.8 | 15.7 | 6.67 | Poor |
Common L/100km to MPG (UK) Conversions
| L/100km | MPG (UK) | MPG (US) |
|---|---|---|
| 3 L/100km | 94.2 | 78.4 |
| 3.5 L/100km | 80.7 | 67.2 |
| 4 L/100km | 70.6 | 58.8 |
| 4.5 L/100km | 62.8 | 52.3 |
| 5 L/100km | 56.5 | 47.0 |
| 5.5 L/100km | 51.4 | 42.8 |
| 6 L/100km | 47.1 | 39.2 |
| 6.4 L/100km | 44.1 | 36.8 |
| 6.5 L/100km | 43.5 | 36.2 |
| 6.6 L/100km | 42.8 | 35.6 |
| 7 L/100km | 40.4 | 33.6 |
| 7.5 L/100km | 37.7 | 31.4 |
| 8 L/100km | 35.3 | 29.4 |
| 8.5 L/100km | 33.2 | 27.7 |
| 9 L/100km | 31.4 | 26.1 |
| 9.5 L/100km | 29.7 | 24.8 |
| 10 L/100km | 28.2 | 23.5 |
| 10.5 L/100km | 26.9 | 22.4 |
| 11 L/100km | 25.7 | 21.4 |
| 11.5 L/100km | 24.6 | 20.5 |
| 12 L/100km | 23.5 | 19.6 |
| 12.5 L/100km | 22.6 | 18.8 |
| 13 L/100km | 21.7 | 18.1 |
| 14 L/100km | 20.2 | 16.8 |
| 15 L/100km | 18.8 | 15.7 |
| 16 L/100km | 17.7 | 14.7 |
| 17 L/100km | 16.6 | 13.8 |
| 18 L/100km | 15.7 | 13.1 |
| 19 L/100km | 14.9 | 12.4 |
| 20 L/100km | 14.1 | 11.8 |
Frequently Asked Questions
How do I convert L/100km to MPG (UK)?
Divide 282.481 by your L/100km value. Example: 8 L/100km = 282.481 ÷ 8 = 35.3 MPG (UK). The constant 282.481 comes from 100 × 4.54609 L ÷ 1.609344 km.
What is a good L/100km in UK terms?
Under 5 L/100km is excellent (roughly 56+ MPG UK — hybrids and efficient diesels). 5–7 is good (40–56 MPG UK). 7–10 is average (28–40 MPG UK). Over 10 L/100km is high consumption (under 28 MPG UK).
Why does MPG (UK) look higher than MPG (US) for the same L/100km?
The Imperial gallon is ~20% larger than the US gallon (4.54609 L vs 3.785 L). The same real-world fuel economy therefore produces a larger MPG number in Imperial gallons. 8 L/100km = 35.3 MPG (UK) = 29.4 MPG (US).
Related Fuel Economy Converters
Bridging Europe's Metric and the UK's Imperial Habits
Fuel-economy labels on modern UK cars show both figures: L/100km (a metric measure of fuel consumed over a fixed distance) and MPG (UK) (an Imperial measure of distance per gallon). Converting between the two is a simple inverse division — MPG (UK) = 282.481 ÷ L/100km — but the practical meaning differs. L/100km is linear: saving 1 L/100km is always the same real-world fuel saving. MPG is non-linear: a jump from 40 to 50 MPG (UK) saves much less than a jump from 20 to 30 MPG (UK), even though both are "+10 MPG".
That's why fleet managers, environmental regulators, and manufacturers in Europe prefer L/100km when comparing vehicles. But in the UK, MPG is still the number drivers quote to each other, and it's what they see on dashboard trip computers and fuel-receipt apps.
Why the Constant Is 282.481
The conversion factor comes from exact definitions:
- 1 Imperial gallon = 4.54609 L
- 1 mile = 1.609344 km
Expressing "miles per gallon" in terms of "litres per 100 km" gives:
MPG (UK) = (100 km ÷ L) × (1 mile ÷ 1.609344 km) × (4.54609 L ÷ 1 gallon) = 282.481 ÷ L/100km
Quick Mental Math: L/100km to MPG (UK)
For fast mental estimates, divide 280 by the L/100km figure:
- 4 L/100km → ~70 MPG (UK) — hybrid / efficient diesel
- 5 L/100km → ~56 MPG (UK) — efficient diesel
- 6 L/100km → ~47 MPG (UK) — good petrol
- 7 L/100km → ~40 MPG (UK) — average family car
- 10 L/100km → ~28 MPG (UK) — SUV / performance car
- 12 L/100km → ~24 MPG (UK) — large SUV / older engine
Reference Table with Common Cases
| Scenario | L/100km | MPG (UK) | Notes |
|---|---|---|---|
| Plug-in hybrid, battery mode | 3.0 | 94.2 | WLTP combined charge-depleting |
| Toyota Prius hybrid | 4.0 | 70.6 | WLTP combined |
| Efficient diesel (e.g. Golf TDI) | 5.0 | 56.5 | WLTP combined |
| Petrol family car (e.g. Focus) | 6.3 | 44.8 | WLTP combined |
| Petrol SUV (e.g. Qashqai) | 7.4 | 38.2 | WLTP combined |
| Large petrol SUV / V6 | 10.0 | 28.2 | Real-world mixed driving |
| Old petrol engine / performance car | 14.0 | 20.2 | Real-world mixed driving |
How L/100km Compares Across Markets
L/100km is the common language you'll find on UK fuel labels, European test cycles (WLTP, NEDC), and most emission-regulation documents. If you're evaluating an imported car, compare the L/100km figures first, then convert to MPG (UK) for the "gut feel" you're used to on UK roads. A WLTP-rated 5.6 L/100km is always the same fuel economy whether you see it on a German, French, or British spec sheet; its equivalent MPG (UK) figure — about 50.4 — is what you'll hear drivers talk about at the pump.
Full Conversion Table
Need a printable reference? See the full L/100km to MPG (UK) conversion table with pre-calculated values, CSV download, and print-friendly layout.
