What this calculator works out
This calculator works out the annual cost of driving to work: fuel, parking and fares, and an allowance for the wear your car accumulates that is not fuel.
Fuel alone substantially understates commuting. Tyres, servicing, depreciation and the shorter life of a higher-mileage car are all real costs, and they are why a per-mile allowance is included alongside the pump price.
Enter your details
Before you calculate
- Enter miles each way, not the round trip. The calculator doubles it.
- Use real-world fuel economy, not the official figure. Commuting is often short-journey driving, where economy is worst.
- Include season tickets and parking permits by dividing the annual cost by 52 for the weekly field.
- For the wear allowance, 10p a mile is a reasonable general figure. HMRC's approved mileage rate of 45p a mile covers fuel and running costs together, so subtracting your fuel cost per mile from that gives a personalised estimate.
A cold engine uses considerably more fuel than a warm one, and a car that never reaches operating temperature suffers more wear per mile. A commute made up of short trips can return economy well below the official figure, which is why using your own measured miles per gallon matters.
How this calculator works
Annual mileage first, then three cost components:
Annual miles = miles each way × 2 × days per week × 52
Fuel = annual miles ÷ mpg × 4.546 litres × price per litre
Parking and fares = weekly amount × 52
Wear = annual miles × pence per mile ÷ 100The 4.546 converts gallons to litres, since miles per gallon uses the imperial gallon while fuel is sold in litres. The calculation excludes insurance, road tax and the value of your time, all of which are real costs of commuting by car.
Worked example: a 12-mile commute
Using the default figures — 12 miles each way, five days a week, 45 mpg, fuel at £1.45 a litre, £10 a week parking and 10p a mile wear:
- Annual mileage: 12 × 2 × 5 × 52 = 6,240 miles
- Fuel: £914.05
- Parking and fares: £10 × 52 = £520.00
- Vehicle wear at 10p a mile: £624.00
- Total: £2,058.05 a year
Over £2,000 of take-home pay, which for a basic rate taxpayer is around £2,850 of gross salary before it is earned. Expressed per commuting day it is roughly £7.90. Both framings are more useful than the annual total when comparing against a season ticket, a shorter commute or working from home.
Common mistakes
- Entering the round trip in the miles field. The calculator already doubles it.
- Using the official mpg figure. Real-world economy on short commutes is usually well below it.
- Counting fuel only. Wear and depreciation are real and roughly comparable in size.
- Forgetting to annualise parking permits and season tickets.
- Comparing against a job's gross salary difference. Commuting is paid from net income.
Frequently asked questions
How do I work out my real miles per gallon?
Fill the tank, note the mileage, drive normally for a full tank, then fill again and record the litres. Miles driven divided by litres used, multiplied by 4.546, gives your actual mpg. Do it over two or three tanks of typical driving for a reliable figure — trip computers are often optimistic by several per cent.
Is 10p a mile a fair wear allowance?
It is a reasonable general figure for a mid-sized car. A more personal estimate comes from HMRC's approved mileage rate of 45p a mile for the first 10,000 business miles, which is intended to cover fuel and all running costs. Subtract your own fuel cost per mile — around 15p in the example above — and the remainder is an evidence-based allowance for everything else.
Can I claim commuting costs against tax?
Ordinary commuting between home and a permanent workplace is not tax-deductible in the UK. Travel to a temporary workplace may be, and if you use your own car for business journeys your employer can pay the approved mileage rate tax-free — or you can claim relief if they pay less. GOV.UK sets out the distinction, which turns on whether the workplace is permanent.
How does this compare with public transport?
Compare the total here against an annual season ticket rather than against a daily fare, since season tickets are usually far cheaper per journey. Include parking at the station if relevant. Many employers also offer season ticket loans, which spread the cost without interest.
Is what I enter stored?
No. Journey details and costs are processed in your browser and never transmitted or retained.
Related tools
References
- GOV.UK — approved mileage allowance payments and tax relief on work travel
- MoneyHelper — guidance on car running costs and commuting expenses
Sources are checked at publication and can change — how I choose and check references.