Car total cost of ownership is the amount you spend to buy, finance, run and eventually sell a vehicle over the time you keep it. The sticker price is only the starting point: interest, insurance, fuel, servicing, repairs, licensing and depreciation can change which car is genuinely affordable. To compare vehicles fairly, estimate these costs over the same ownership period and expected annual distance, then subtract likely resale proceeds. Use quotes and vehicle-specific information where possible, and treat uncertain repair and resale estimates as ranges rather than guarantees.
A useful estimate covers the whole period you expect to own the car. It includes the cost of acquiring it, the cost of financing it, regular and unexpected running expenses, and the amount you can recover when you sell it. Some costs are easy to predict, such as a quoted insurance premium; others, particularly repairs and resale value, need an estimate.
A straightforward calculation is:
Total ownership cost = acquisition cost + finance interest and fees + insurance + fuel or energy + maintenance and repairs + licensing and other use costs − resale proceeds.
Include depreciation by subtracting the expected sale value from the purchase price. Don’t then add depreciation as a separate cost as well: that would count the same loss twice. Likewise, choose one consistent way to account for loan payments.
| Calculation approach | What to include | Best used for | Common mistake |
|---|---|---|---|
| Ownership-cost view | Purchase price, finance interest and fees, running costs, then subtract expected resale proceeds | Comparing the underlying cost of owning different cars | Adding loan principal on top of the purchase price |
| Cash-flow view | Deposit and loan repayments, fees, running costs, then subtract sale proceeds | Understanding money paid out during the ownership period | Adding the purchase price again after counting repayments |
For a financed car, loan repayments include principal as well as interest. If you use the ownership-cost view, count the vehicle’s purchase price and the interest and fees, not the principal twice. If you use the cash-flow view, count the deposit and repayments rather than adding the purchase price separately. When selling a car with finance still owing, account for the outstanding balance when working out how much of the sale proceeds you actually retain.
Two cars can look very different depending on how long you keep them and how far you drive. A fuel-efficient vehicle may save more for someone covering a high annual distance, while a low-mileage driver may place greater weight on insurance, financing or depreciation. Before collecting figures, decide on a realistic ownership period and annual distance for your own plans.
Use the same assumptions for each car. Compare the same number of years, similar driving distances, and equivalent insurance cover. If you expect to use one car mostly for short urban trips and another for longer journeys, account for those different patterns when estimating fuel use and wear. A monthly cost can help with budgeting, but retain the total for the full period too: a low monthly figure can reflect a longer loan rather than a cheaper car.
Where an estimate is uncertain, record a lower, middle and higher case instead of pretending it is exact. Resale value and future repairs are especially difficult to forecast. Testing how the total changes under less favourable assumptions can show whether your choice depends on an optimistic resale price or unusually low maintenance costs.
Depreciation is the difference between what you pay for a vehicle and what you receive when you sell it. It is not a bill you pay each month, but it can be one of the largest parts of the car’s economic cost. A cheaper car is not automatically cheaper to own if it loses more value over your holding period.
Estimate resale value using comparable vehicles, taking account of age, model, condition, mileage and equipment. Asking prices are not necessarily the amounts sellers receive, and a future sale price cannot be guaranteed. If the estimate is uncertain, use a cautious figure in your main comparison and note how a stronger or weaker resale result would affect it. For a vehicle with a loan, also check that your expected sale proceeds would cover the balance you may need to repay.
Compare borrowing offers by their total cost, not just the advertised repayment. Check the interest rate, loan term, establishment or account fees, any deposit requirement and whether a final balloon payment applies. A longer term may reduce each instalment while increasing the amount paid in interest over time. Make sure you are comparing the same purchase amount and term, and include any fee that applies to one offer but not another.
Also consider whether the loan term matches how long you expect to keep the car. If you plan to sell before the loan is paid off, the outstanding balance could reduce or exceed the equity available from the sale. The repayment schedule and likely resale value should therefore be considered together.
Insurance premiums vary with the vehicle, the driver, where and how the car is used, the chosen cover and the excess. Obtain quotes for the specific cars you are considering rather than relying on a general estimate for a model or vehicle type. Keep the cover and excess as similar as possible when comparing quotes; otherwise, a lower premium may come with a different level of protection.
Insurance is a recurring expense, so multiply the quoted premium across your planned ownership period, while allowing for the fact that future premiums can change. Check what the policy covers and what you would have to pay yourself after a claim. A car with a lower purchase price may not produce a lower insurance bill.
Estimate fuel spending using your expected distance, realistic fuel consumption for the way you drive, and a current local fuel price. A basic calculation is:
Estimated fuel cost = annual distance ÷ 100 × consumption per 100 km × price per litre.
Use the fuel-consumption measure appropriate to the vehicle, and remember that published figures may not match your driving conditions. Traffic, trip length, load and driving style can affect actual use. If you are comparing a petrol, hybrid or electric vehicle, estimate the energy cost for each using your likely mix of journeys and where you expect to refuel or charge. Don’t assume a particular charging arrangement is available without checking that it suits your home and routine.
Routine servicing, replacement tyres and ordinary wear items should be part of the estimate, not treated as surprises. Check the maintenance schedule and ask for records when assessing a used car. The condition of the specific vehicle matters: two cars of the same model and age can have different near-term needs depending on their history, mileage and how they have been maintained.
Repairs are harder to predict, especially as a vehicle ages. Research likely maintenance needs for the model and ask a qualified mechanic to assess a used car before purchase. Set aside a repair allowance that reflects the vehicle’s condition and your ability to absorb an unexpected bill. A very low allowance can make an older or less thoroughly inspected car appear artificially cheap.
Include vehicle licensing, any inspection costs that apply, parking, tolls and other regular expenses linked to how you use the car. In New Zealand, check the vehicle’s licensing and Warrant of Fitness status and note when the next costs may fall due; requirements depend on the vehicle and its circumstances. For a used car, confirm its current status rather than assuming that a seller’s description covers everything.
These expenses may be smaller than the purchase price or depreciation, but they still affect the total. Include them consistently for each candidate, particularly if one vehicle’s condition or intended use means extra checks, work or travel costs are likely.
Keep the working in a simple spreadsheet or written cost sheet. Show the period, distance and assumptions beside each estimate. That makes it easier to spot why one vehicle appears cheaper and to update the result when you receive a real quote or inspection report.
Consider two hypothetical cars. Candidate A costs less to buy but is expected to use more fuel and may sell for less after the same ownership period. Candidate B costs more upfront but has lower estimated energy spending and stronger expected resale value. These are assumptions for a comparison, not claims about particular makes or models.
Candidate A may still be the more affordable choice if its purchase-price advantage is large enough, or if you drive relatively little. Candidate B may cost less overall if the savings in running costs and resale loss outweigh its higher initial price. The only useful answer comes from putting both vehicles through the same calculation, using quotes and estimates that reflect your circumstances.
This comparison also shows why headline monthly repayments can mislead. They may not include insurance, fuel, maintenance or the loss in resale value, and they can differ because of loan terms. Compare the full ownership period first; use the monthly equivalent afterward to check whether the likely cost fits your budget.
If a candidate only looks affordable under the most optimistic assumptions, reconsider it or gather better information before committing. A vehicle with a slightly higher estimated total may still be the right choice if it better suits your needs, but the trade-off should be clear before you buy.
No. Depreciation is one part of total ownership cost: it is the loss between the purchase price and resale proceeds. The full calculation also accounts for financing, insurance, fuel or energy, maintenance, repairs and other costs of keeping the car.
They can be, but choose an accounting approach and avoid counting the purchase price and loan principal twice. In an ownership-cost calculation, include the purchase price plus finance interest and fees. In a cash-flow calculation, count the deposit and repayments instead, then account for the money received from selling the car and any loan balance that must be cleared.
Compare similar vehicles with relevantly similar age, mileage, condition and equipment, and treat asking prices as a guide rather than a guaranteed sale price. If the estimate is uncertain, use a cautious figure and test how a lower sale price changes your result.
Use the same annual distance for every candidate, realistic consumption figures and a current local fuel price. Adjust the estimate for the journeys you actually make, since driving conditions and trip patterns can affect real-world consumption.
Yes, as an estimate or allowance rather than a certain expense. Review the vehicle’s maintenance history and condition, and get a qualified inspection for a used car when appropriate. Leaving likely repairs out can make a vehicle look cheaper than it is.
Yes. A higher-priced vehicle could have lower financing costs, insurance, energy use, maintenance needs or depreciation over your chosen period. Compare the complete estimates under the same assumptions instead of treating purchase price as the final measure of value.
Before choosing, compare each car over the period you expect to own it and include both likely resale proceeds and costs beyond the showroom price. The resulting car total cost of ownership gives you a more realistic basis for judging affordability and deciding what to verify before purchase.
