b2KIT

Car Depreciation Calculator

Estimate vehicle depreciation over time and calculate future resale value by year.

Tested tool guide Tested browser tools Checked August 16, 2026

What Car Depreciation Calculator does, with a checked example

Enter the price you paid or plan to pay, how long you plan to keep the car, and the annual rate at which it loses value, and the tool projects the vehicle's worth for each year of ownership, ending with its future resale value. Each year's figure is the previous year's value reduced by the same annual percentage, so the dollar loss shrinks every year while the percentage stays constant. The result that surprises most people: the largest dollar drop is always the first year, so a new car loses more in its first 12 months than in any later year.

Worked example

A concrete input and expected output from the current implementation.

Input

Purchase price: $25,000 | Years to keep: 4 | Annual depreciation rate: 20%

Expected output

Year 1: $20,000 | Year 2: $16,000 | Year 3: $12,800 | Year 4: $10,240 | Total lost: $14,760 (59.04% of purchase price)

Each year's value is the previous year's value reduced by 20%, so the dollar loss falls from $5,000 in year one to $2,560 in year four while the percentage stays constant. The final row is the estimated resale value; purchase price minus cumulative loss is $25,000 - $14,760 = $10,240, which reconciles the two figures.

How the result is produced

1

Year-by-year compounding

The tool applies the annual depreciation rate to the previous year's value, not to the original price, so each year's loss is computed against a shrinking base. That produces a running table: the same percentage every year, with dollar losses that decline steadily. Reading the row for the year you expect to sell gives the estimated resale value at that age.

2

Loss versus remaining value

Besides each year's value, the tool reports the cumulative picture: the total amount of the purchase price already lost and the share of the original price the vehicle still holds. The two figures are complementary - resale value plus cumulative loss always equals the purchase price - which makes it easy to see both what the car is worth and what keeping it has cost.

Good uses

  • Planning when to sell: compare the projected value at different ages to see whether the car is losing more per year than it costs to keep, and pick a sale year before the remaining value gets small.
  • Negotiating a trade-in: bring the projected value for your car's age to the dealership as a reference point, so the trade-in offer has a number to be checked against rather than taken on faith.
  • Choosing new versus used: run both candidates through the tool - a new car's first-year dollar drop usually exceeds the entire annual depreciation of a two-year-old used car, which changes the real cost comparison.

Limits and checks

  • Not an appraisal: the tool works only from the numbers you enter and knows nothing about your car's condition, mileage, accident history, or local demand. A result of $10,000 means "under these assumptions," not "a dealer will pay $10,000."
  • The rate drives everything: over five years, 12% versus 18% annual depreciation can change the projected value by thousands of dollars. The rate you choose matters more than a small difference in purchase price, so question the rate before you trust the result.
  • Year one is usually worse in reality: the tool applies one constant rate to every year, but actual cars typically shed a bigger share in their first year - the drop that comes from leaving the lot - than in later years, so the projection's first-year loss is often an underestimate.

Common questions

Is this what a dealer will actually offer me for trade-in?

Probably not. Trade-in offers start from wholesale or auction value, which runs below the retail resale figure this tool estimates, and the dealer then adjusts for condition, mileage, and how easy the car is to sell. Expect an offer below the tool's number, and expect a private sale to land closer to it.

Does it account for my car's mileage or condition?

No. It uses only the price, the years, and the depreciation rate you enter, and it applies the same annual percentage to every year. An exceptionally clean, low-mileage car will beat the projection; a high-mileage or damaged one will fall short of it. Treat the result as the baseline for a typical car, then adjust by judgment.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.

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