Car Total Cost of Ownership Calculator
Adds up everything a car costs over the time you own it and gives a figure per year, per month and per kilometre. Depreciation is included, because it is usually the biggest item and the one most often ignored.
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The formula
per year = (price − resale) ÷ years + fuel + insurance + tax + maintenance + tyres + other + interest fuel = km ÷ 100 × L/100 km × price per litre interest ≈ amount financed × rate ÷ 2
Depreciation is spread evenly over the ownership period — a simplification, since cars lose most value early, but it gives the right average. Interest on an amortising loan averages about half the rate on the original amount, because the balance falls to zero over the term.
What to watch out for
What drives the total:
- Depreciation is typically 40–60% of the cost of a car bought new and kept five years. Buying at three years old roughly halves it.
- Fuel is 15–30% for most drivers — less than it feels, because it is paid weekly.
- Maintenance rises with age as depreciation falls, which is why an older car is cheaper overall but less predictable.
For an electric car enter kWh/100 km and the electricity price; the fuel line works the same way. Oil changes, services and repairs all belong in the maintenance figure — a typical modern car needs 150–300 a year in routine servicing before anything breaks.
Frequently Asked Questions
How much does it really cost to own a car per year?
For a 25,000 car kept five years with a 12,000 resale, 15,000 km a year at 7 L/100 km and typical fixed costs, about 6,000 a year — 500 a month, or 0.40 per kilometre. Depreciation alone is 2,600 of it.
What is the biggest cost of owning a car?
Depreciation, for anything under about eight years old — commonly 40% or more of the total. Fuel is usually second and insurance third, though for a young driver insurance can top the list.
How do I calculate cost per kilometre?
Total annual cost divided by annual distance. The figure falls as you drive more, because the fixed costs — depreciation, insurance, tax — are spread over more kilometres; only fuel, tyres and some maintenance scale with distance.