How much is my car actually costing me each month?
Most people know their fuel bill and their insurance. Fewer add up servicing, tyres, repairs, parking and the value the car loses each year. Put them together and the real monthly figure is often a surprise.
The costs to include
| Cost | How to count it |
|---|---|
| Fuel or charging | Add up a few months of fill-ups and average it. |
| Insurance | Yearly premium ÷ 12 (or your monthly payment, including any interest). |
| Vehicle tax | Yearly amount ÷ 12. |
| MOT | The fee ÷ 12 (the maximum for a car is £54.85), plus any repairs it needed. |
| Servicing | Last year's service bill(s) ÷ 12. |
| Tyres | Price of a set ÷ how many years they last, then ÷ 12. |
| Repairs | What you spent in the last year or two, averaged per month. |
| Parking, tolls, cleaning, breakdown cover | Easy to forget — add them in. |
| Finance | Your monthly payment, if you have one. |
| Depreciation | (What you paid − what it's worth now) ÷ months you've owned it. |
A simple worked example
These figures are made up to show the method — use your own.
| Item | Per year | Per month |
|---|---|---|
| Fuel | £1,440 | £120 |
| Insurance | £600 | £50 |
| Tax | £195 | £16.25 |
| MOT | £54.85 | £4.57 |
| Service | £240 | £20 |
| Tyres (£400 a set every 3 years) | £133 | £11.11 |
| Repairs | £300 | £25 |
| Total running costs | £2,962.85 | £246.90 |
If the car also loses £1,500 of value a year, that is another £125 a month — taking the true cost to about £372 a month.
Cost per mile
Divide the yearly total by the miles you drove. In the example, £2,962.85 over 8,000 miles is about 37p a mile in running costs. Cost per mile is the fairest way to compare two cars, or to decide whether a trip is cheaper by car or by train.
Why your real MPG matters
Fuel is usually the biggest single running cost, and real-world MPG is often well below the official figure. Short journeys, cold starts, heavy traffic, under-inflated tyres and roof boxes all push it down. Logging your fill-ups shows your actual figure — and a sudden drop can be an early sign that something needs looking at.
Ways to bring the number down
- Check tyre pressures monthly — under-inflated tyres cost fuel and wear faster.
- Shop around at renewal for insurance and breakdown cover.
- Keep up with servicing so small jobs don't become big ones.
- Act on MOT advisories before they turn into fails.
Let MotoTrac do the sums
Log fill-ups and bills as you go and MotoTrac works out your real MPG, cost per mile and monthly spend — see the running cost tracker.
Sources
This guide is general information for UK vehicle owners. Your owner's manual and your mechanic or MOT tester have the final word for your vehicle.