™AutoFire™ tools / Inventory & profit
Free Car Depreciation Calculator
Model vehicle value using your own annual decline rate and value floor. See a year-by-year depreciation table without a valuation lookup.
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For informational use only. Your chosen decline rate is a scenario assumption, not a live appraisal, guaranteed resale value, or tax depreciation method.
How to use this tool
- 1Enter a starting vehicle value, your annual percentage assumption, and the number of years.
- 2Choose a value floor to prevent the scenario from dropping below that amount.
- 3Review each year's loss and value retained. Use independent appraisal evidence for an actual vehicle.
How the result is built
Year-n value = the larger of your value floor or starting value × (1 − annual decline rate)ⁿ. The percentage applies to the remaining value, so yearly dollar losses usually decline. This is a resale scenario, not a tax depreciation method.
An example from the lot
Start at $30,000, assume a 15% annual decline, and set a $5,000 floor. The first modeled year ends at $25,500; the second ends at $21,675. Changing the assumed rate creates a different scenario rather than a market forecast.
A practical guide to this calculation
Build a transparent vehicle-value scenario when you need to discuss how a percentage decline compounds over several years. The calculator uses your starting value, chosen decline rate, and value floor. It is especially useful for comparing assumptions; it has no vehicle database and does not claim to appraise a particular VIN.
Worked example using the starting values
Start at $30,000, assume a 15% annual decline, and set a $5,000 floor. The first modeled year ends at $25,500; the second ends at $21,675. Changing the assumed rate creates a different scenario rather than a market forecast.
- Scenario value at end
- $13,311.16
- Total modeled depreciation
- $16,688.84
- Value retained
- 44.37%
This example remains here when you change the interactive fields above. Your scenario results are shown inside the tool and can be downloaded as a CSV.
Choose assumptions you can explain
Start from the value relevant to your question, such as a supported current valuation or a purchase-price scenario. The annual decline percentage is supplied by you. The example rate is illustrative and is not a statement about the depreciation of every brand, age, mileage, or vehicle condition.
The value floor is another assumption. It prevents the modeled value from falling below that amount but does not guarantee a salvage price or future sale. If the floor is above the starting value, the inputs contradict a declining-value scenario, so the tool asks you to correct them.
Understand percentage decline versus a fixed dollar loss
A 15% decline on $30,000 removes $4,500 in year one. Applying the same rate to the remaining $25,500 removes $3,825 in year two. The dollar loss shrinks because the base changes. Subtracting $4,500 every year would be a different model and will not match this table.
Each row shows the year-end scenario value, that year's dollar loss, and cumulative loss from the starting point. The value-retained percentage compares the final value with the start. A zero starting value leaves that percentage undefined; it does not imply a meaningful return or an increase in value.
Use scenarios alongside actual inventory evidence
An annual model is not designed to price a unit that has sat on a lot for another week. For inventory decisions, combine your own appraisal evidence and comparable listings with the separate holding-cost and profit tools. Those tools answer cost questions; this one answers the arithmetic of a chosen value-decline assumption.
For a useful comparison, download one scenario, change only the annual decline percentage, and download another. Keep the starting value, years, and floor identical so the difference is interpretable. The calculation supports up to twenty years and stays local, with no background price feed or market prediction.
Common questions
Is this tax depreciation for a dealership or business vehicle?
No. The table models a percentage decline in an assumed value. It does not apply tax basis rules, recovery periods, depreciation elections, deductions, or accounting methods. Use the appropriate records and professional guidance for tax or book treatment.
Why do two vehicles need different assumptions?
Starting age, condition, mileage, equipment, and the relevant market can differ. This tool deliberately asks you to supply the assumption rather than presenting one default rate as a universal fact. Check actual evidence before using a scenario in a purchase discussion.
What happens at 0% or 100% decline?
At zero, the modeled value stays at the starting value. At 100%, it drops to the entered floor after the first year. The floor cannot exceed the starting value, and the calculator rejects negative rates and non-whole modeling periods.
Method and reference material
Formula and example reviewed October 29, 2026. For another task, browse the free dealership tools directory.