How It Works
Declining-balance depreciation: value reduces by a fixed percentage of the prior year’s value each year.
Value = Purchase Price x (1 - depreciation rate)^years
- As a general pattern, value loss is steepest in the first year and eases as the car ages — but the exact rate varies widely by model, mileage, condition, and market.
- Reputation matters but is not a rule: some trucks and reliable models tend to hold value better, while many luxury cars lose it faster. Use your specific model’s history where possible.
Worked Example
$35,000 car, 3 years old, 15%/year.
Total Lost
$13,506 (38.6%)
A $35,000 car worth about $21,494 after three years has lost roughly $13,506, or close to $4,500 a year on average, purely to depreciation before any running costs.
Car Depreciation: The Largest Cost of Ownership, and Why It Front-Loads
Depreciation is usually the biggest line in the cost of driving
When people tally the cost of a car they think about fuel, insurance, and maintenance — and overlook the expense that typically dwarfs all of them: depreciation, the value the car quietly sheds just by getting older. On the $35,000 default, three years of ownership erase about $13,506, roughly $4,500 a year, before a single tank of fuel or oil change. For most newer vehicles, that value loss is the single largest cost of ownership, which is exactly why it belongs in the budget when you compare buying, leasing, or keeping what you have.
This calculator estimates that loss so you can see it as a number rather than feel it only at trade-in time. You supply the original price, the car’s current age, and an annual depreciation rate; it projects the current value and what the car might be worth at 5 and 10 years old. Because resale value swings with mileage, condition, and demand, treat the output as a planning estimate, not a quote.
Why the declining-balance curve front-loads the loss
The model uses declining-balance depreciation: each year the car keeps a fixed percentage of the value it had the year before, not a fixed number of dollars. At a 15% rate it is worth 85% of last year’s value each year — so $35,000 becomes about $29,750 after year one, then 85% of that, and so on. Because the percentage always applies to a shrinking base, the dollar loss is largest early and tapers every year after; in the year-by-year table the first year’s drop is far bigger than the eighth year’s.
That front-loading is the practical heart of the matter, and it is why a fixed-dollar mental model misleads — it understates the early hit and overstates the later one. It is also the strongest argument for buying a lightly used car: letting the first owner absorb the steepest part of the curve can deliver most of a vehicle’s useful life at a meaningfully lower price. As a broad pattern, value loss is steepest in the first year and eases with age, but how steep varies widely by model.
The rate is a guess — treat it that way
Everything this tool produces hinges on the one number you cannot know precisely: the annual depreciation rate. As a rough guide, many mainstream cars average somewhere around 15-20% a year over their early years, which is why 15% is the default — but this is a convention, not a measured fact for your car. Some trucks and models with strong reliability reputations tend to hold value better; many luxury cars and EVs with fast-moving technology can lose it faster. These are tendencies driven by supply, demand, and perception, not fixed rates you can rely on.
So if you have real data for your specific make, model, and trim — from historical resale listings or a valuation guide — use it in place of the default, and run a couple of rates to see the range. The headline value is only as good as the rate behind it, and a five-point swing in the rate changes the projected value substantially over a decade.
What the formula cannot see
A single, constant rate is a deliberate simplification, and several real-world forces sit outside it. Mileage is the obvious one: a car driven far more than average usually sells for less, while genuinely low mileage can support a higher price — and this model tracks time, not odometer reading, so adjust your expectations if your usage is unusual. Condition, service history, accident records, desirable options, and even shifts in fuel prices or model redesigns all move resale value in ways no fixed percentage captures.
There are also limits you can influence and limits you cannot. Keeping mileage moderate, maintaining records, and fixing cosmetic damage can soften depreciation, but they cannot stop it. Results here are estimates for general guidance, not an appraisal or financial advice. Before you actually buy or sell, check a recognized valuation guide or get a dealer or independent appraisal for a figure grounded in your car’s real condition and your local market.