MPG (UK) to L/100km Converter
Convert Imperial miles per gallon (MPG UK) to liters per 100 km (L/100km). Formula: L/100km = 282.481 ÷ MPG (UK).
How to Convert MPG (UK) to L/100km
The conversion is inverse: since MPG measures distance per unit of fuel and L/100km measures fuel per unit of distance, the formula is a division, not a multiplication.
- L/100km = 282.48094 ÷ MPG (UK)
The constant 282.48094 comes from exact definitions: 1 Imperial gallon = 4.54609 L and 1 mile = 1.609344 km, so 100 km ÷ 1 UK gallon gives 282.48094.
MPG (UK) ↔ L/100km Reference Table
Common fuel-economy values expressed in all four units. Click any MPG (UK) value for a dedicated conversion page.
| MPG (UK) | MPG (US) | L/100km | km/L | Category |
|---|---|---|---|---|
| 20 | 16.7 | 14.1 | 7.08 | Below average |
| 30 | 25.0 | 9.42 | 10.6 | Average |
| 40 | 33.3 | 7.06 | 14.2 | Good |
| 45 | 37.5 | 6.28 | 15.9 | Good |
| 50 | 41.6 | 5.65 | 17.7 | Good |
| 55 | 45.8 | 5.14 | 19.5 | Very good |
| 60 | 50.0 | 4.71 | 21.2 | Very good |
| 70 | 58.3 | 4.04 | 24.8 | Excellent |
Common MPG (UK) to L/100km Conversions
| MPG (UK) | L/100km | km/L |
|---|---|---|
| 16 MPG | 17.7 | 5.66 |
| 17 MPG | 16.6 | 6.02 |
| 18 MPG | 15.7 | 6.37 |
| 19 MPG | 14.9 | 6.73 |
| 20 MPG | 14.1 | 7.08 |
| 21 MPG | 13.5 | 7.43 |
| 22 MPG | 12.8 | 7.79 |
| 23 MPG | 12.3 | 8.14 |
| 24 MPG | 11.8 | 8.50 |
| 25 MPG | 11.3 | 8.85 |
| 26 MPG | 10.9 | 9.20 |
| 27 MPG | 10.5 | 9.56 |
| 28 MPG | 10.1 | 9.91 |
| 29 MPG | 9.74 | 10.3 |
| 30 MPG | 9.42 | 10.6 |
| 31 MPG | 9.11 | 11.0 |
| 32 MPG | 8.83 | 11.3 |
| 33 MPG | 8.56 | 11.7 |
| 34 MPG | 8.31 | 12.0 |
| 35 MPG | 8.07 | 12.4 |
| 36 MPG | 7.85 | 12.7 |
| 37 MPG | 7.63 | 13.1 |
| 38 MPG | 7.43 | 13.5 |
| 39 MPG | 7.24 | 13.8 |
| 40 MPG | 7.06 | 14.2 |
| 41 MPG | 6.89 | 14.5 |
| 42 MPG | 6.73 | 14.9 |
| 43 MPG | 6.57 | 15.2 |
| 44 MPG | 6.42 | 15.6 |
| 45 MPG | 6.28 | 15.9 |
| 46 MPG | 6.14 | 16.3 |
| 47 MPG | 6.01 | 16.6 |
| 48 MPG | 5.89 | 17.0 |
| 49 MPG | 5.76 | 17.3 |
| 50 MPG | 5.65 | 17.7 |
| 51 MPG | 5.54 | 18.1 |
| 52 MPG | 5.43 | 18.4 |
| 53 MPG | 5.33 | 18.8 |
| 54 MPG | 5.23 | 19.1 |
| 55 MPG | 5.14 | 19.5 |
| 56 MPG | 5.04 | 19.8 |
| 57 MPG | 4.96 | 20.2 |
| 58 MPG | 4.87 | 20.5 |
| 59 MPG | 4.79 | 20.9 |
| 60 MPG | 4.71 | 21.2 |
| 61 MPG | 4.63 | 21.6 |
| 62 MPG | 4.56 | 21.9 |
| 63 MPG | 4.48 | 22.3 |
| 64 MPG | 4.41 | 22.7 |
| 65 MPG | 4.35 | 23.0 |
| 70 MPG | 4.04 | 24.8 |
| 75 MPG | 3.77 | 26.6 |
| 80 MPG | 3.53 | 28.3 |
| 90 MPG | 3.14 | 31.9 |
| 100 MPG | 2.82 | 35.4 |
Frequently Asked Questions
How do I convert MPG (UK) to L/100km?
Divide 282.481 by your Imperial MPG value. Example: 40 MPG (UK) = 282.481 ÷ 40 = 7.06 L/100km. The constant 282.481 comes from 100 × 4.54609 L ÷ 1.609344 km.
What is a good MPG in the UK?
55+ MPG (UK) is very good (modern diesel and hybrid cars). 40–55 is good (efficient petrol cars). 30–40 is average (typical family cars). Below 30 is high consumption (large SUVs or older vehicles).
Why is the MPG to L/100km conversion not linear?
MPG is an inverse metric (distance per fuel) while L/100km is direct (fuel per distance). They are reciprocals. Doubling MPG halves L/100km: 30 MPG (UK) = 9.42 L/100km, 60 MPG (UK) = 4.71 L/100km.
Is MPG (UK) the same as MPG (US)?
No. The Imperial (UK) gallon is 4.54609 L, while the US gallon is 3.785 L. The Imperial gallon is ~20% larger, so 40 MPG (UK) equals roughly 33.3 MPG (US) — same fuel economy, different units.
Related Fuel Economy Converters
Understanding Imperial MPG and L/100km
Imperial MPG (sometimes written MPG UK) is based on the Imperial gallon of 4.54609 litres, still used in the United Kingdom and a handful of Commonwealth countries. Because an Imperial gallon is about 20% larger than a US gallon, an Imperial MPG figure is always about 20% higher than the equivalent US MPG number for the same vehicle. A car rated 40 MPG (UK) actually delivers the same real-world fuel economy as a car rated roughly 33 MPG (US) or 7.06 L/100km.
The two metrics (MPG and L/100km) describe fuel economy from opposite ends. MPG tells you how far a unit of fuel takes you; L/100km tells you how much fuel you use for a fixed distance. Because they are reciprocals, the conversion is non-linear: doubling MPG halves L/100km. That's why a jump from 20 to 30 MPG (UK) — a 50% improvement — saves a hefty 4.7 L/100km, while jumping from 50 to 60 MPG saves less than 1 L/100km.
Why the UK Still Uses MPG
Most of Europe switched to L/100km decades ago, but the UK has retained MPG alongside metric units. UK official fuel-economy labels (WLTP) now show both figures, and magazines, dealers, and owner forums continue to quote MPG (UK) as the primary number. When comparing a UK review to a continental-European one, always check which gallon is in use — a "35 MPG" figure from the UK is worse than it looks when converted to US MPG and better than it looks when converted to L/100km.
Quick Mental Math: MPG (UK) to L/100km
The exact formula is L/100km = 282.481 ÷ MPG (UK). For round estimates:
- 30 MPG (UK) → about 9.4 L/100km
- 40 MPG (UK) → about 7.1 L/100km
- 50 MPG (UK) → about 5.6 L/100km
- 60 MPG (UK) → about 4.7 L/100km
- 70 MPG (UK) → about 4.0 L/100km
The shortcut "280 ÷ MPG" gets you within 1% of the real figure — accurate enough for on-the-road mental estimates.
Reference Table with UK Vehicle Examples
Approximate fuel economy for common UK vehicle types. Actual figures vary with driving style, road type, load, and weather.
| Vehicle Example | MPG (UK) | L/100km | Notes |
|---|---|---|---|
| Large SUV (e.g. Range Rover petrol) | 22 | 12.8 | Combined WLTP |
| Family SUV (e.g. Nissan Qashqai petrol) | 38 | 7.4 | Combined WLTP |
| Mid-size petrol (e.g. Ford Focus) | 45 | 6.3 | Combined WLTP |
| Efficient diesel (e.g. Skoda Octavia TDI) | 60 | 4.7 | Combined WLTP |
| Hybrid compact (e.g. Toyota Yaris Hybrid) | 68 | 4.2 | Combined WLTP |
| Plug-in hybrid (e.g. Toyota Prius PHEV) | 90 | 3.1 | Mixed, charge-depleting |
When to Convert Rather Than Compare
If you're reading a UK review and planning to buy in the US (or vice-versa), always convert first. A UK car rated "50 MPG" is not the same as a US car rated 50 MPG — the UK figure corresponds to roughly 42 MPG (US). Conversely, a European car advertised at "5.6 L/100km" is the same as 50 MPG (UK) or 42 MPG (US). Using L/100km is the safest common ground for cross-market comparisons.
Full Conversion Table
Need a printable reference? See the full MPG (UK) to L/100km conversion table with pre-calculated values, CSV download, and print-friendly layout.
