If you’re trying to work out how much your next trip might cost, this easy fuel cost calculator guide will help you estimate petrol or diesel expenses using real UK fuel prices from November 2025.
No app or tool needed - just a simple formula and a quick reference table.
How to Calculate Fuel Cost per Mile
You can work out the cost of fuel per mile using this basic formula:
Fuel Cost per Mile = (Fuel Price per Litre ÷ Miles per Litre)
Or in detail:
Fuel Cost per Mile = (Fuel Price per Litre × 4.546) ÷ Miles per Gallon
Here’s how to find what you need:
-
Fuel price per litre: Use the current UK average from the RAC or AA. (As of November 2025, petrol averages £1.35 per litre, diesel around £1.43 per litre.)
-
Miles per gallon (mpg): Check your car’s average mpg from your dashboard or manufacturer site.
-
Miles per litre (mpl): Divide your mpg by 4.546 (1 UK gallon = 4.546 litres).
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Example Fuel Cost Calculations (November 2025)
|
Vehicle Type |
Fuel Type |
Average MPG |
Fuel Price per Litre |
Cost per Mile |
Cost for 100 Miles |
|---|---|---|---|---|---|
|
Small hatchback |
Petrol |
50 mpg |
£1.35 |
£0.12 |
£12.00 |
|
Medium SUV |
Petrol |
40 mpg |
£1.35 |
£0.15 |
£15.00 |
|
Diesel saloon |
Diesel |
55 mpg |
£1.43 |
£0.12 |
£12.00 |
|
Large SUV |
Diesel |
35 mpg |
£1.43 |
£0.19 |
£19.00 |
|
Electric car |
Electricity |
– |
£0.27 /kWh |
~£0.06 |
£6.00 |
How Much Does It Cost to Drive 20, 50, or 100 Miles?
|
Distance |
Petrol Car (40 mpg) |
Diesel Car (50 mpg) |
Electric Car |
|---|---|---|---|
|
20 miles |
£3.00 |
£2.30 |
£1.20 |
|
50 miles |
£7.50 |
£5.75 |
£3.00 |
|
100 miles |
£15.00 |
£11.50 |
£6.00 |
|
300 miles |
£45.00 |
£34.50 |
£18.00 |
(Based on UK fuel averages for November 2025.)
Current UK Fuel Prices (November 2025)
-
Average petrol price per litre: £1.35
-
Average diesel price per litre: £1.43
-
Average electric charging rate (home): £0.27 per kWh
Source: RAC Fuel Watch and UK Government weekly fuel price report (Nov 2025).
For a deeper understanding of how efficiency affects EV running costs, you can read our Miles per kWh Explained – EV Efficiency Guide.
Petrol vs Diesel vs Electric Cost per Mile
|
Type |
Average Cost per Mile |
Notes |
|---|---|---|
|
Petrol |
12–15p |
Most common fuel type; varies by engine size |
|
Diesel |
11–14p |
More efficient on long journeys |
|
Electric |
5–8p |
Cheaper to run but depends on charging cost |
Quick Reference: Common Queries Answered
-
How much petrol per mile UK? Around 12–15p per mile.
-
How much diesel per mile UK? About 11–14p per mile.
-
Cost of fuel per mile UK (2025)? Average around 13p per mile.
-
How much does 100 miles of petrol cost? Between £12 and £15.
-
How much does it cost to drive a mile UK? From 6p for EVs to 15p for petrol.
Fuel Cost Formula Recap
Fuel Cost (£) = (Journey Miles × Fuel Price per Litre × 4.546) ÷ MPG
Use this to estimate costs for any distance - whether 20 miles or 400 miles - based on November 2025 prices
Having these figures updated within your own calculations ensures the most accurate trip planning and helps you track savings if you’re comparing fuel types before car leasing or buying a new one.
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
Any tool that uses up-to-date prices and accurate MPG or EV efficiency data. This page uses November 2025 national averages.
Between £12 and £15 depending on vehicle mpg.
Around 13p per mile, based on £1.35 /litre.
Yes. Enter your fuel price, MPG or miles per kWh, and trip distance for a quick estimate.
Electric, particularly if you charge at home using off-peak electricity.
Diesel engines typically cost 2–3p less per mile on motorway runs.
Yes, electric cars average 5–8p per mile on home charging rates.