Car Trade-In Value Calculator
Estimate what a dealer is likely to offer for your car as a trade-in.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Scenario estimate only, not a dealer quote. Enter a comparable market-value baseline before adjustments. The model applies fixed condition, mileage and accident factors, then subtracts the dealer-margin percentage for the trade-in estimate. Both outputs use the same condition, mileage and accident adjustments; real offers depend on vehicle details and local market data.
Worked example
calculated with the default values below
Comparable market-value baseline 18,000 USD · Condition Good (0.88) · Odometer 60,000 mi · Expected miles for its age 60,000 mi · Accident history No accidents reported · Dealer margin 12 % Modeled private-party value 15,840 USD · Modeled trade-in value 13,939 USD · Modeled mileage factor 1.000 ×
General background references
Disclaimer
These calculators give estimates for general information only. Real fuel consumption, performance and range vary with driving style, load, terrain, temperature and vehicle condition. Do not rely on these results for towing limits, payload or braking decisions — use the rating plate of your vehicle.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
P = V × c × m × a; T = P × (1 − d ÷ 100); m = clamp[1 − (mi − mi_expected) ÷ 100000, 0.85, 1.08]
- P
- Modeled private-party value
- T
- Modeled trade-in value
- V
- Comparable market-value baseline, USD
- c
- Condition factor
- m
- Capped mileage factor
- a
- Accident-history factor
- d
- Dealer-margin percentage
The same condition, mileage and accident factors apply to both estimates. These are scenario assumptions, not market data or dealer quotes.
Frequently asked questions
How are the private-party and trade-in estimates calculated?
Both estimates start with your comparable market-value baseline and apply the same fixed condition, mileage and accident-history factors. The trade-in estimate then subtracts the dealer-margin percentage. The factors are scenario assumptions, not market data; actual offers depend on the vehicle and local market.
Does this calculator give a dealer quote?
No. It provides a modeled comparison only. Use current listings for comparable vehicles and request an in-person appraisal for an actual offer.