About Diminished Value
Understand your rights and how the 17c formula works to estimate your car's lost value after an accident.
What Is Diminished Value?
When your vehicle is involved in an accident, it loses value even after being fully repaired. This loss in value is called diminished value (DV). A car with an accident on its history report is worth less than an identical car without one — buyers and dealers both pay less for vehicles with prior damage.
Diminished value claims allow you to recover that lost value from the at-fault driver's insurance company. In most states, you have the legal right to file a diminished value claim as a third-party claimant (when the other driver was at fault).
The 17c Formula
The 17c formula originates from a Georgia court case (State Farm Mutual Automobile Insurance Co. v. Mabry) and has become the most widely used method for calculating diminished value. Here's how it works:
Start with your vehicle's base value
The pre-accident market value based on year, make, model, and condition.
Apply the 10% cap
The formula caps diminished value at 10% of the vehicle's value.
Apply damage multiplier
A factor based on the severity of damage (minor, moderate, or major).
Apply mileage multiplier
Lower-mileage vehicles have a higher diminished value claim.
How to File a Claim
- Calculate your diminished value using our free calculator to get an estimate range.
- Gather documentation including the accident report, repair receipts, and vehicle history.
- Contact the at-fault driver's insurance and submit a formal diminished value demand letter.
- Negotiate — the initial offer is often lower than your actual diminished value. Use your estimate as leverage.
- Consider a professional appraisal if the insurance company's offer is significantly below your estimate.
State-by-State Coverage
Diminished value claims are recognized in most U.S. states for third-party claims (when the other driver was at fault). Georgia is the most favorable state for DV claims, but most states allow them in some form.
A few states, like Michigan with its no-fault insurance system, make DV claims more difficult. Check your state's specific laws or consult an attorney for guidance on your situation.