Choose the baseline first
Depreciation describes a reduction in value relative to a starting point. State whether that starting point is an original new price, your purchase price or another estimate. Those baselines answer different questions.
If a hypothetical car falls from 20,000 to 16,200, the absolute loss is 3,800 and the total loss is 19%. These inputs are an example, not an observed rate for any model.
Total loss and annualized loss
Total percentage loss is (starting value − ending value) ÷ starting value × 100. For a period longer than zero years, a compound annualized rate is 1 − (ending value ÷ starting value) raised to the power of 1 ÷ years.
A constant 10% annual scenario applied to 20,000 produces 18,000 after one year and 16,200 after two. That is compounding, not subtracting the same amount every year. If the ending value is higher, the calculation describes appreciation.
Why a chart average is different
Different cars entering the recorded sample can change the average even when no individual asking price changes. Mileage, condition, trim and market also affect comparability. Our model history therefore does not establish a model-specific depreciation forecast.
The calculator lets you enter your own scenario or starting and ending values. It does not choose an expected market rate for you, assess a vehicle, or calculate tax depreciation.