Calculate your vehicle's real-world fuel economy, compare to UK averages, and convert between MPG and L/100km.
| Vehicle type | Typical real-world MPG | L/100km equivalent |
|---|---|---|
| Small petrol car (e.g. VW Polo, Ford Fiesta) | 40–50 MPG | 5.7–7.1 L/100km |
| Family petrol car (e.g. VW Golf, Ford Focus) | 35–45 MPG | 6.3–8.1 L/100km |
| Small diesel car | 50–65 MPG | 4.3–5.7 L/100km |
| Family diesel car | 45–60 MPG | 4.7–6.3 L/100km |
| SUV / crossover (petrol) | 28–38 MPG | 7.4–10.1 L/100km |
| Hybrid (e.g. Toyota Yaris, Prius) | 55–75 MPG | 3.8–5.1 L/100km |
| Van / light commercial | 25–40 MPG | 7.1–11.3 L/100km |
Manufacturer MPG figures are measured under standardised WLTP test conditions, which include a mix of urban, suburban, and motorway driving at controlled temperatures. Real-world driving typically achieves 10–20% lower than the official figure due to factors including driving style, traffic conditions, cold weather, air conditioning use, tyre pressure, and vehicle load. Our calculator uses your actual fuel usage to give you your true real-world MPG.
To convert from MPG (UK) to litres per 100km, use the formula: L/100km = 282.48 ÷ MPG. For example, 40 MPG = 282.48 ÷ 40 = 7.06 L/100km. To convert in reverse: MPG = 282.48 ÷ L/100km. Our converter tab handles this automatically.
MPG is not directly used in car insurance calculations, but engine size and vehicle type — which correlate with fuel economy — do affect premiums. More fuel-efficient vehicles tend to have smaller engines and fall into lower insurance groups, which can mean lower premiums. Electric vehicles often attract lower insurance costs due to lower risk profiles.