Depreciation % Retained Calculator
Calculate what percentage of its original value a car has retained after depreciation.
Last updated:
What this tool does
This calculator computes the percentage of original purchase price that a vehicle has retained, using the ratio formula (Current Value ÷ Original Value) × 100. It requires two inputs—current market value and original purchase price—and returns the retained percentage, the percentage lost, and a descriptive value band. The calculation is a simple arithmetic ratio; accuracy depends entirely on the accuracy of the two input values.
How Depreciation % Retained Calculator works
This tool computes what fraction of a car's original purchase price remains as current market value, expressed as a percentage. The output shows both the percentage retained and the percentage lost, along with the absolute monetary value lost. A descriptive band (ranging from 'Held value strongly' at 80%+ down to 'Near-end-of-life value' below 20%) provides context for the result, though these labels are purely observational and carry no advisory weight.
The formula
The calculation uses a straightforward ratio:
Retained % = (Current Value ÷ Original Value) × 100
Lost % = 100 − Retained %
Value Lost = Original Value − Current Value
All three outputs are derived from the same two inputs with no hidden coefficients or jurisdiction-specific adjustment factors.
Where this method is most accurate
The ratio is mathematically exact for the two numbers entered. Accuracy in real-world terms depends entirely on the accuracy of the current valuation and the original purchase price. Market valuations can vary between trade-in, private-sale, and retail figures; the calculator treats the entered current value as a single point estimate. The original value should reflect the actual purchase price paid, including any factory options or dealer fees if those are to be included in the depreciation assessment.
What this tool does not do
This calculator does not forecast future depreciation, adjust for mileage or condition, or incorporate regional market trends. It does not account for modifications, accident history, or service records. The descriptive bands are observational labels only and do not constitute appraisals or recommendations to buy, sell, or hold a vehicle. The tool performs no time-series analysis; it compares two static values at a single point in time.
Disclaimer
This calculator is an educational mathematics tool. It does not provide vehicle valuations, financial advice, or warrant any particular outcome. Actual depreciation depends on make, model, mileage, condition, market demand, and many other factors not captured by this ratio. Always consult current market data and, where financial decisions are involved, a qualified professional.
Questions
- What does 'percentage retained' mean?
- Percentage retained is the current market value expressed as a fraction of the original purchase price. A car that cost 25,000 new and is now worth 15,000 has retained 60% of its value.
- Why does the tool show descriptive bands like 'Typical depreciation'?
- The bands (80%+, 60–80%, 40–60%, 20–40%, below 20%) are observational labels that provide context for the numeric result. They do not constitute appraisals or recommendations and carry no advisory weight.
- Can I use insurance settlement value or trade-in offer as the current value?
- Any figure can be entered as current value; the calculator treats it as a single point estimate. Trade-in, private-sale, and retail valuations often differ, so the result will vary depending on which figure is used.
- Does the calculator adjust for mileage or condition?
- No. The tool compares two static monetary values without adjusting for mileage, accident history, service records, modifications, or market trends. Those factors are reflected only if they are already incorporated into the current-value input.
- What if my current value is higher than the original price?
- The calculator will return an error if current value exceeds original value, because the retention formula is designed for depreciation scenarios. Appreciation (e.g., classic or collectible vehicles) falls outside the scope of this ratio.
Sources & Methodology
The calculator divides current market value by original purchase price and multiplies by 100 to yield retained percentage. The formula is the standard percentage-retention ratio: (Current ÷ Original) × 100. This is a fundamental arithmetic operation with no external coefficients; the logic is implemented directly in the MotorMath engine as documented in the code above.