Financial Law
Diminished Value Calculator
Estimate the loss of value your car suffered after an accident using the standard 17c formula.
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April 2026
Diminished Value Calculator
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How Does a Diminished Value Calculator Work?
Our tool uses the standard 17c Formula, which is widely adopted by insurance companies to estimate loss of value after a collision. The formula starts with a base loss (capped at 10% of the vehicle's pre-accident value) and reduces it based on two main factors: Damage Severity and Mileage.
The 17c Formula Mechanics
- Base Loss of Value: 10% of your car's Kelley Blue Book (KBB) or NADA clean retail value before the crash.
- Damage Multiplier: Ranges from 1.00 (severe structural damage) down to 0.00 (no structural damage/minor cosmetic).
- Mileage Multiplier: High mileage reduces the diminished value claim. Ranges from 1.00 (under 20k miles) down to 0.00 (over 100k miles).
Pro Tip: Appraisal vs. 17c Formula
The 17c formula often results in lowball offers from insurance companies. If your vehicle is brand new or a high-end luxury car, consider hiring an independent diminished value appraiser to get a more accurate (and usually higher) assessment.
Frequently Asked Questions
Diminished value is the loss of market value a vehicle suffers after being in an accident and repaired. Even fully repaired, buyers will pay less for a car with an accident history.
The 17c formula is a standard equation created by the insurance industry (often associated with State Farm v. Mabry in Georgia) to calculate diminished value. It applies a 10% base cap to the car's Book Value, then applies multipliers based on the severity of the damage and the vehicle's mileage.
Typically, you can only claim diminished value if you are not at fault for the accident (a third-party claim). Some states do not allow first-party diminished value claims against your own collision coverage unless you live in states like Georgia.
No, this provides an estimate based on the insurance industry's standard 17c formula. Attorneys and independent appraisers often argue for higher amounts because the 17c formula is heavily favored toward insurance companies.