Fuel Cost Per Mile: How Much Does Driving Really Cost?
Fuel cost depends on three main things:
• how far you drive
• your vehicle’s fuel economy
• the price you pay for fuel
Two drivers covering the same distance can therefore have very different fuel costs.
This guide shows how to calculate fuel cost per mile and compares example cars achieving 40, 50 and 60 MPG.
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The short answer
A more fuel-efficient car uses less fuel to travel the same distance.
For example, using an illustrative petrol price of £1.45 per litre:
• a 40 MPG car costs about 16.5p per mile
• a 50 MPG car costs about 13.2p per mile
• a 60 MPG car costs about 11.0p per mile
These figures represent fuel only.
They do not include insurance, servicing, tyres, depreciation, tax, finance or other vehicle costs.
Fuel cost per mile at 40, 50 and 60 MPG
| Fuel Economy | Fuel Cost Per Mile | 100-Mile Journey | 1,000 Miles | 10,000 Miles |
|---|---|---|---|---|
| 40 MPG | £0.165 | £16.48 | £164.80 | £1,647.96 |
| 50 MPG | £0.132 | £13.18 | £131.84 | £1,318.37 |
| 60 MPG | £0.110 | £10.99 | £109.86 | £1,098.64 |
These examples use an illustrative fuel price of £1.45 per litre.
Enter your actual local fuel price in the ToolNest Fuel Cost Calculator for a personalised result.
How to calculate fuel cost per mile
For a UK MPG figure, first work out how many imperial gallons are needed:
Gallons used = miles travelled ÷ MPG
Convert imperial gallons to litres:
Litres used = imperial gallons × 4.54609
Then calculate fuel cost:
Fuel cost = litres used × price per litre
Finally:
Fuel cost per mile = total fuel cost ÷ miles travelled
Example: 100 miles at 50 MPG
Assume:
Distance:
100 miles
Fuel economy:
50 MPG
Fuel price:
£1.45 per litre
Fuel required:
100 ÷ 50 = 2 imperial gallons
2 × 4.54609 = approximately 9.09 litres
Fuel cost:
9.09 × £1.45 = approximately £13.18
So the fuel cost for the 100-mile journey is approximately:
£13.18
Fuel cost per mile:
approximately 13.2p
How much difference does fuel economy make?
Using the same illustrative £1.45 per litre fuel price:
A 40 MPG car travelling 10,000 miles uses approximately:
1,136.5 litres
Estimated fuel cost:
£1,647.96
A 60 MPG car travelling the same 10,000 miles uses approximately:
757.7 litres
Estimated fuel cost:
£1,098.64
Difference:
approximately £549.32 per year
This shows how relatively small differences in MPG can become significant over higher annual mileages.
How much can commuting cost in fuel?
Consider someone driving a 40-mile round trip to work, five days per week.
That is:
200 miles per week
Over 48 working weeks:
9,600 miles per year
At 50 MPG and £1.45 per litre, estimated annual fuel cost would be approximately:
£1,265.64
This is fuel only and does not include the other costs of running the vehicle.
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Why your real MPG may differ
The MPG displayed by a vehicle or quoted by a manufacturer may not exactly match real-world fuel economy.
Actual fuel consumption can be affected by:
• traffic
• short journeys
• cold weather
• driving speed
• acceleration and braking
• tyre pressures
• vehicle load
• air conditioning
• hills
• road conditions
• engine condition
For the best estimate, use the MPG your vehicle actually achieves over normal driving.
Does motorway driving use less fuel?
Cars can often achieve better fuel economy during steady-speed driving than during repeated acceleration and braking in urban traffic.
However, very high motorway speeds can increase aerodynamic drag and fuel consumption.
The most efficient speed depends on the vehicle, engine, gearing and driving conditions.
How much difference does 10p per litre make?
A small difference in pump price can add up over a year.
A 50 MPG car travelling 10,000 miles uses approximately:
909.2 litres
At £1.40 per litre:
approximately £1,272.91
At £1.50 per litre:
approximately £1,363.83
Difference:
approximately £90.92 per year
What is the difference between MPG and litres per 100km?
MPG measures how far a vehicle travels using one gallon of fuel.
A higher MPG figure means better fuel efficiency.
Litres per 100km measures how much fuel is needed to travel 100 kilometres.
With L/100km, a lower figure means better fuel efficiency.
Use the ToolNest Fuel Efficiency Calculator to convert between UK MPG, US MPG, litres per 100km and kilometres per litre.
Fuel is only part of the cost of driving
Fuel is one of the most visible vehicle costs, but it is not the whole cost of running a car.
Other costs can include:
• insurance
• servicing
• repairs
• tyres
• vehicle tax
• MOT
• depreciation
• finance interest
• parking
• tolls
A car with lower fuel costs is not automatically the cheapest vehicle overall.
Fuel Cost FAQs
How much does 50 MPG cost per mile?
At an illustrative fuel price of £1.45 per litre, a UK 50 MPG vehicle costs approximately 13.2p per mile in fuel.
How much fuel does a 100-mile trip use at 50 MPG?
Approximately 2 imperial gallons, or about 9.09 litres.
Is 60 MPG much cheaper than 40 MPG?
Yes over higher mileage. In the 10,000-mile example used here, 60 MPG saves approximately £549 in fuel compared with 40 MPG at £1.45 per litre.
Does MPG include petrol price?
No. MPG measures fuel efficiency. The financial cost also depends on the price paid per litre.
Is UK MPG the same as US MPG?
No. UK MPG uses the larger imperial gallon, while US MPG uses the smaller US gallon. The same vehicle therefore has different numerical MPG values depending on the system used.
Does idling use fuel?
Yes. An engine can consume fuel while the vehicle is stationary, which can reduce real-world MPG.
Sources and methodology
The calculations in this guide use:
1 imperial gallon = 4.54609 litres
Worked examples use an illustrative fuel price of:
£1.45 per litre
This price is used only to demonstrate the calculation and is not presented as the current UK average pump price.
Actual fuel costs depend on the price paid and the vehicle’s real-world fuel economy.