RealCost Tool
Fuel Cost Per Mile Calculator UK
Fuel cost per mile is one of the clearest ways to understand how expensive a petrol or diesel car really is to drive.
Use this calculator to estimate cost per mile, cost per 100 miles, weekly fuel cost, monthly fuel cost, yearly fuel cost and estimated fuel used per year.
Work out cost per mile
See how much each mile costs based on fuel price and your car’s MPG.
Budget fuel over time
Turn yearly mileage into practical weekly, monthly and annual fuel estimates.
Compare cars properly
Compare different MPG figures to see how fuel economy affects real running cost.
Calculate your fuel cost per mile
Enter your fuel price per litre, vehicle MPG and miles driven per year to estimate your cost per mile and yearly fuel spend.
This calculator estimates fuel cost only. Real fuel cost can vary depending on driving style, traffic, tyre pressure, vehicle load, weather, route type and actual MPG.
Fuel cost is not the full cost of driving
Fuel cost per mile is useful, but it does not include insurance, road tax, servicing, tyres, repairs, depreciation, parking or finance. Use it as one part of the total car cost picture.
RealCost note: MPG tells you how efficient a car is. Fuel cost per mile shows what that efficiency actually means in pounds and pence.
What the calculator includes
The calculator uses three simple inputs to estimate fuel cost per mile and yearly fuel spend.
Fuel price per litre
Enter the petrol or diesel price you normally pay per litre.
Vehicle MPG
Enter your car’s miles per gallon. Use a realistic real-world MPG figure if possible.
Miles driven per year
Enter your estimated annual mileage to calculate weekly, monthly and yearly fuel cost.
What the results tell you
The results show fuel cost in useful everyday formats, from each mile to a full year of driving.
Fuel cost per mile
The main result. It shows how much each mile costs in petrol or diesel.
Fuel cost per 100 miles
Useful for comparing journeys, commutes and car efficiency.
Weekly fuel cost
Your estimated fuel cost per week based on annual mileage.
Monthly fuel cost
A practical monthly fuel estimate for budgeting.
Yearly fuel cost
How much fuel could cost across a full year of driving.
Fuel used per year
Estimated annual fuel use in litres.
Example fuel cost result
This example uses £1.50 per litre, 45 MPG and 10,000 miles per year.
Fuel price
£1.50/L
Vehicle MPG
45 MPG
Annual mileage
10,000
Fuel cost per mile
£0.15
Cost per 100 miles
£15.15
Monthly fuel cost
£126.28
Yearly fuel cost
£1,515.33
What this means: A car that feels cheap to fill can still cost over £1,500 a year in fuel if it covers regular mileage.
Which fuel calculator should you use?
RealCost has different fuel tools for different decisions. Use the one that matches your question.
Fuel Cost Per Mile Calculator
Use this when you want ongoing fuel cost per mile, per month and per year.
Fuel Cost Calculator UK
Use this for a quick known-distance fuel cost using miles, fuel price and MPG.
Trip Fuel Cost Planner UK
Use this for journeys, return trips, traffic allowance and split-cost planning.
How to use the result properly
Fuel cost per mile becomes most useful when you compare it against your real mileage.
Use real-world MPG
Advertised MPG can be optimistic. Use your actual MPG if you know it.
Compare different cars
Run the calculator with different MPG figures before choosing a car.
Check yearly impact
A small cost-per-mile difference can become large if you drive high mileage.
What changes fuel cost per mile?
The calculator gives a good estimate, but real-world driving can move the number up or down.
Hard acceleration, late braking and high speeds can reduce MPG.
Stop-start driving usually uses more fuel than steady motorway driving.
Underinflated tyres can reduce efficiency and increase wear.
Extra passengers, luggage or roof boxes can increase fuel use.
Short town trips often cost more per mile than longer steady journeys.
A few pence per litre can add up across high annual mileage.
Lower MPG vs higher MPG
The more you drive, the more difference MPG can make to your yearly fuel cost.
Lower MPG car
- Uses more fuel per mile
- Higher cost per 100 miles
- More expensive for commuting
- Costs build up quickly over high mileage
Be careful if: you drive long distances regularly.
Higher MPG car
- Uses less fuel per mile
- Lower cost per 100 miles
- Better for regular journeys
- Can save more over higher mileage
Useful if: you commute or drive often.
When this calculator is most useful
Use it when you want to understand fuel cost as an ongoing running cost.
What to calculate next
Use these tools to turn fuel cost into a better driving or ownership decision.
Commute Calculator UK
Estimate daily, weekly, monthly and yearly driving-to-work costs.
Electric vs Petrol Calculator
Compare petrol running costs with EV charging costs.
EV Charging Cost Calculator UK
Estimate EV charging cost per charge, per mile and per year.
Related guides
Use these guides if fuel cost is part of a wider car-buying or high-mileage decision.