Fuel Cost Per Mile UK 2026: Petrol, Diesel & Electric Compared
Key takeaways
- Average petrol cost per mile in May 2026: 17–22p (depending on MPG)
- Average diesel cost per mile in May 2026: 15–19p (depending on MPG)
- Electric car home charging cost per mile: 6–9p
- The formula is simple: (fuel price × 4.546) ÷ MPG = pence per mile
- HMRC's approved mileage rate for employees is 45p per mile (first 10,000 miles) — covering fuel, wear, and depreciation
Knowing your fuel cost per mile is one of the most useful numbers you can have as a driver — it tells you the true cost of every journey, helps you compare vehicles, and is essential for accurate HMRC mileage claims or expense reporting.
This guide gives you the exact figures for May 2026, the formula to calculate your own number, and ready-made tables for the most common MPG ranges.
Current UK fuel prices (May 2026)
Fuel prices fluctuate weekly. The figures above reflect the RAC Fuel Watch national average for May 2026. Use our fuel cost calculator to enter the exact price at your local station for the most accurate result.
How to calculate fuel cost per mile
The formula uses the fact that one UK gallon equals 4.546 litres:
Formula: Cost per mile (pence) = (Fuel price in pence per litre × 4.546) ÷ MPG
Example (petrol, 157p/litre, 40 MPG):
(157 × 4.546) ÷ 40 = 713.7 ÷ 40 = 17.8p per mile
Petrol cost per mile table (May 2026)
At 157p per litre. Find your car's real-world MPG on Honest John or Fuelly for the most accurate figure — manufacturer claimed MPG is often 10–20% optimistic.
| MPG | Pence per mile | Cost per 100 miles | Cost per 10,000 miles/yr |
|---|---|---|---|
| 25 MPG (heavy SUV, older car) | 28.5p | £28.50 | £2,850 |
| 30 MPG (average older petrol) | 23.8p | £23.80 | £2,380 |
| 35 MPG (typical family hatchback) | 20.4p | £20.40 | £2,040 |
| 40 MPG (efficient petrol) | 17.8p | £17.80 | £1,780 |
| 45 MPG (small petrol / mild hybrid) | 15.9p | £15.90 | £1,590 |
| 50 MPG (petrol hybrid) | 14.3p | £14.30 | £1,430 |
| 55 MPG (efficient hybrid) | 13.0p | £13.00 | £1,300 |
| 60 MPG (top hybrid / small petrol) | 11.9p | £11.90 | £1,190 |
Diesel cost per mile table (May 2026)
At 170p per litre. Diesel engines typically return higher MPG, which partly offsets the higher fuel price.
| MPG | Pence per mile | Cost per 100 miles | Cost per 10,000 miles/yr |
|---|---|---|---|
| 35 MPG (older diesel) | 22.1p | £22.10 | £2,210 |
| 40 MPG (average diesel) | 19.3p | £19.30 | £1,930 |
| 45 MPG (efficient diesel) | 17.2p | £17.20 | £1,720 |
| 50 MPG (good modern diesel) | 15.5p | £15.50 | £1,550 |
| 55 MPG (very efficient diesel) | 14.1p | £14.10 | £1,410 |
| 60 MPG (top diesel) | 12.9p | £12.90 | £1,290 |
| 70 MPG (hybrid diesel) | 11.0p | £11.00 | £1,100 |
Electric car cost per mile table (May 2026)
Electric car efficiency is measured in miles per kWh (mi/kWh). Most EVs return 3–4 mi/kWh in real-world conditions.
| Efficiency | Home tariff (25p/kWh) | EV tariff (12p/kWh) | Public rapid (55p/kWh) |
|---|---|---|---|
| 2.5 mi/kWh (large EV, cold weather) | 10.0p | 4.8p | 22.0p |
| 3.0 mi/kWh (average EV) | 8.3p | 4.0p | 18.3p |
| 3.5 mi/kWh (efficient EV) | 7.1p | 3.4p | 15.7p |
| 4.0 mi/kWh (very efficient EV) | 6.3p | 3.0p | 13.8p |
| 4.5 mi/kWh (small/light EV) | 5.6p | 2.7p | 12.2p |
Real-world vs claimed efficiency: EV range figures are tested under the WLTP standard. Real-world efficiency is typically 15–25% lower, particularly in cold weather and at motorway speeds. Always use real-world mi/kWh figures from owner communities (Fuelly, Bjorn Nyland's data) rather than manufacturer claims when budgeting fuel costs.
HMRC mileage rates for 2026
If you use your own car for work, you can claim back fuel costs from your employer or HMRC using the approved mileage allowance payment (AMAP) rates. These are not purely fuel costs — they cover wear and tear, insurance, and depreciation too:
| Vehicle type | First 10,000 miles | Over 10,000 miles |
|---|---|---|
| Cars and vans (petrol/diesel/hybrid) | 45p per mile | 25p per mile |
| Electric cars | 45p per mile | 25p per mile |
| Motorcycles | 24p per mile | 24p per mile |
| Bicycles | 20p per mile | 20p per mile |
Advisory fuel rates (company cars): If you drive a company car, HMRC sets lower Advisory Fuel Rates (AFRs) for fuel-only reimbursement. For petrol cars with engines up to 1400cc, the current AFR is 14p per mile. Check GOV.UK advisory fuel rates for the current figures by engine size and fuel type.
Common cars and their real-world fuel cost per mile
Using real-world MPG data from Fuelly and Honest John (May 2026 fuel prices):
| Car | Real-world MPG | Cost per mile |
|---|---|---|
| Ford Fiesta 1.0 EcoBoost (petrol) | 41 MPG | 17.4p |
| Volkswagen Golf 1.5 TSI (petrol) | 38 MPG | 18.8p |
| Toyota Yaris Hybrid (petrol hybrid) | 58 MPG | 12.3p |
| Vauxhall Astra 1.5 CDTi (diesel) | 52 MPG | 14.9p |
| BMW 3 Series 320d (diesel) | 48 MPG | 16.1p |
| Tesla Model 3 (electric, home) | 3.8 mi/kWh | 6.6p |
| Nissan Leaf (electric, home) | 3.5 mi/kWh | 7.1p |
| Volkswagen ID.4 (electric, home) | 3.2 mi/kWh | 7.8p |
⛽ Calculate your exact cost per mile
Enter your car's MPG (or mi/kWh for EVs), your local fuel price, and your annual mileage to get your personalised fuel cost figures.
Use the Fuel Cost Calculator →Frequently asked questions
What is the average fuel cost per mile in the UK in 2026?
At May 2026 fuel prices (petrol 157p/litre, diesel 170p/litre), the average fuel cost per mile for a petrol car returning 35 MPG is approximately 20p per mile. For a diesel returning 48 MPG it is approximately 16p per mile. Electric cars charged at home cost around 6–9p per mile at standard tariff rates, or as low as 3–4p on an overnight EV tariff.
How do I calculate my fuel cost per mile?
Divide the fuel price per litre by 4.546 to get the cost per UK gallon, then divide by your car's MPG figure. Simplified: Cost per mile (pence) = (Fuel price in pence per litre × 4.546) ÷ MPG. Our fuel cost calculator does this automatically.
Is diesel cheaper per mile than petrol?
It depends on your car's efficiency. Diesel fuel costs more per litre (approximately 170p vs 157p in May 2026), but diesel engines typically return higher MPG. A diesel car returning 48 MPG costs around 16p per mile, while a petrol car at 35 MPG costs around 20p. However, a petrol car returning 45+ MPG can match or beat diesel cost per mile.
Also useful
Sources
- RAC Fuel Watch — UK average fuel prices May 2026
- BEIS — Weekly road fuel prices statistics
- HMRC — Approved Mileage Allowance Payments
- HMRC — Advisory fuel rates for company cars
- Fuelly — Real-world MPG data from UK drivers