If you want to work out petrol cost per mile in the UK, this guide shows you how to calculate it using current UK fuel prices as of January 2026.
You do not need an app or online tool. Just your fuel price, your car’s MPG, and a simple formula.
Diesel and electric running costs are also included so you can compare fuel types clearly.
Petrol Cost Per Mile UK (2026)
Based on UK average prices as of 1 January 2026:
-
Petrol: £1.44 per litre
-
Diesel: £1.52 per litre
-
Home electric charging: £0.28 per kWh (Based on the January Ofgem Price Cap)
Using these figures:
-
Petrol costs around 13 to 16 pence per mile
-
Diesel costs around 12 to 15 pence per mile
-
Electric driving costs around 7 to 9 pence per mile
Actual costs depend on your car’s MPG and how you drive, but these ranges reflect typical UK use.
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How to Calculate Fuel Cost Per Mile
You can calculate fuel cost per mile using this simple formula.
Fuel cost per mile formula
Fuel cost per mile (£) = (Fuel price per litre × 4.546) ÷ MPG
Why 4.546?
One UK gallon contains 4.546 litres.
What you need
-
Fuel price per litre: Use UK averages or your local pump price
-
MPG: From your dashboard or manufacturer figures
Example Fuel Cost Calculations (UK, January 2026)
|
Vehicle type |
Fuel |
Average MPG/Efficiency |
Fuel price |
Cost per mile |
Cost per 100 miles |
|
Small hatchback |
Petrol |
50 mpg |
£1.44 |
£0.13 |
£13.00 |
|
Medium SUV |
Petrol |
40 mpg |
£1.44 |
£0.16 |
£16.00 |
|
Diesel saloon |
Diesel |
55 mpg |
£1.52 |
£0.13 |
£13.00 |
|
Large SUV |
Diesel |
35 mpg |
£1.52 |
£0.20 |
£20.00 |
|
Electric car |
Electric |
3.5 miles/kWh |
£0.28 / kWh |
~£0.08 |
£8.00 |
Figures are based on UK averages and typical real-world MPG.
How Much Does Petrol Cost for 20, 50, or 100 Miles?
|
Distance |
Petrol (40 mpg) |
Diesel (50 mpg) |
Electric (3.5 m/kWh) |
|
20 miles |
£3.20 |
£2.80 |
£1.60 |
|
50 miles |
£8.00 |
£7.00 |
£4.00 |
|
100 miles |
£16.00 |
£14.00 |
£8.00 |
|
300 miles |
£48.00 |
£42.00 |
£24.00 |
These examples use average UK fuel prices as of 1 January 2026.
Current UK Fuel Prices (January 2026)
-
Petrol: £1.44 per litre
-
Diesel: £1.52 per litre
-
Home EV charging: £0.28 per kWh
Prices are based on:
-
RAC Fuel Watch
-
UK Government weekly fuel price data
-
Ofgem energy price cap guidance (Effective 1 January 2026)
Fuel prices change regularly, so use your local rates for the most accurate results.
Petrol vs Diesel vs Electric Cost Per Mile
|
Fuel type |
Average cost per mile |
Notes |
|
Petrol |
13 to 16p |
Common for town and mixed driving |
|
Diesel |
12 to 15p |
Better fuel economy on long journeys |
|
Electric |
7 to 9p |
Lowest cost when charging at home |
Electric cars are cheapest to run per mile, but upfront cost and charging access still matter.
Fuel Cost Formula Recap
Fuel cost (£) = (Miles driven × Fuel price per litre × 4.546) ÷ MPG
You can use this formula to:
-
Estimate trip costs
-
Compare petrol and diesel
-
Understand real running costs before leasing or buying
Also check below links:
-
No Deposit Car Leasing – spread the cost without upfront payments
-
Electric Car Lease Deals – drive the latest EVs with lower running costs
-
Used Electric Car Leasing – affordable way to go electric
FAQs: Fuel Cost Calculator UK (2026)
Around 13 to 16 pence per mile, based on January 2026 prices.
About £16 for a car averaging 40 mpg.
Roughly 14.5 pence per mile for most petrol cars.
Diesel can be slightly cheaper per mile due to better MPG, especially on long journeys.
Yes. Home charging usually costs significantly less per mile compared to petrol and diesel.
Yes. Use the formula above with your own MPG and fuel price.