Who uses it
Owners comparing a repair payout with the resale hit, often when filing against the at-fault driver’s insurer.
US auto insurance · 17c estimate
Diminished Value Calculator
Estimate how much a repaired car is worth less in the US market after an accident. Enter pre-loss value, mileage, and damage severity to run the 17c formula insurers commonly use.
Formula at a glance
- Base — 10% of pre-accident value
- Damage — 0.00 to 1.00 by severity
- Mileage — steps down every 20,000 miles
- Result is a claim starting point, not a payout
Vehicle details
Estimate inherent diminished value with the US 17c formula. Enter the car’s value before the crash, current mileage, and how severe the damage was.
17c estimate
Inherent diminished value after a proper repair. Insurers often start here; a documented market loss can be higher.
Press Calculate diminished value to see the 17c loss and the value left after that deduction.
What is a diminished value calculator?
A diminished value calculator estimates the US market-value loss on a vehicle after a crash and a proper repair. Buyers pay less for a car with an accident history. That gap — pre-loss value minus post-repair value — is inherent diminished value.
This tool uses the 17c formula that many US insurers apply: 10% of pre-accident value, adjusted for damage severity and mileage. It is a starting estimate for a claim, not a settlement offer.
What it measures
Inherent loss after quality repairs. It does not price sloppy bodywork or the repair invoice itself.
Typical claim path
Most states treat this as a third-party claim. Your own collision policy often excludes it. Georgia is the best-known first-party exception.
Why 17c is conservative
The formula caps the loss at 10% before further cuts. Comparable sales and an appraisal often support more.
How to use this diminished value calculator
Use numbers from before the crash, not the repaired car’s asking price.
- Enter pre-accident valueUse a US fair-market figure (dealer retail, KBB, or NADA) for a comparable car the day before the loss.
- Enter mileageThe 17c mileage factor steps down every 20,000 miles and reaches zero at 100,000.
- Choose damage severityMatch the structural level of the repairs. Cosmetic-only damage scores zero under 17c.
- Read the estimateCompare the 17c figure with dealer quotes or an appraisal before you accept an insurer number.
How the 17c formula works
Diminished value = pre-loss value × 10% × damage factor × mileage factor
| Input | Factor |
|---|---|
| Base cap | 10% of pre-accident value |
| Severe structural damage | 1.00 |
| Major panel and structure damage | 0.75 |
| Moderate damage | 0.50 |
| Minor damage | 0.25 |
| No structural damage | 0.00 |
| Mileage bands | 1.00, then 0.80, 0.60, 0.40, 0.20, and 0.00 at 100,000+ |
Example: a $28,000 car, moderate damage (0.50), and 45,000 miles (0.60) gives $28,000 × 0.10 × 0.50 × 0.60 = $840.
Accuracy of the results
This is the standard 17c worksheet, not a state-by-state legal ruling. Georgia’s Supreme Court addressed an insurer’s duty to assess diminished value in State Farm v. Mabry (2001). The 17c chart became the common industry method afterward.
What it models well
- The 10% cap insurers start from
- Standard damage and mileage multipliers
- A clear dollar figure you can compare with an offer
What can change the real outcome
- State law and whether the claim is first-party or third-party
- Prior accidents, title brand, or incomplete repairs
- Actual comps and a written appraisal
- Your share of fault in a comparative-negligence state
Diminished value calculator FAQs
Common questions about US diminished value and the 17c estimate.
What is a diminished value calculator?
A diminished value calculator estimates the US market-value loss on a vehicle after a crash and a proper repair. Buyers pay less for a car with an accident on its history, even when the body shop restores the appearance and function. That gap is inherent diminished value. This tool applies the 17c formula insurers often use: 10% of the pre-accident value, adjusted for damage severity and mileage. The figure is a starting point for a claim discussion, not a settlement, a repair invoice, or a measure of poor bodywork.
What is the 17c formula?
Diminished value equals pre-accident value times 10%, times a damage factor, times a mileage factor. Damage runs from 1.00 for severe structural harm down to 0.00 for cosmetic-only repairs. Mileage steps down every 20,000 miles and reaches zero at 100,000. The method spread after Georgia’s State Farm v. Mabry decision, when insurers needed a worksheet for post-repair loss. Many carriers treat the result as a low opening number. Comparable sales and a written appraisal often support a larger claim.
Can I claim this on my own policy?
In most states you claim diminished value against the at-fault driver’s liability insurer, not your own collision policy. Your policy often pays to repair the car and excludes the resale loss that remains afterward. Georgia is the best-known exception: after State Farm v. Mabry, first-party claims against your own insurer are recognized there. A few other states allow them in narrower situations. Fault share, policy wording, and state law all change the outcome, so read your contract and confirm the rule where the crash occurred before you rely on this estimate.
Does cosmetic damage count?
Not under the standard 17c chart. If the repairs are cosmetic and no structural part was damaged, the damage factor is 0.00 and the formula returns $0. That does not mean a buyer will ignore the accident. A reported collision can still lower offers, especially on a newer or higher-priced car. People document that gap with dealer trade-in quotes, private-party comps, or an independent appraisal that compares the repaired car with no-accident cars of the same year, mileage, and trim.
What value should I enter?
Enter the car’s US fair market value on the day before the crash, not the repaired car’s asking price and not the body-shop bill. Dealer retail, Kelley Blue Book, and J.D. Power (NADA) are common sources for a comparable vehicle of the same year, mileage, trim, and condition. Retail, private-party, and trade-in prices are different numbers. Pick one type and use it both for the pre-loss value and for any later comparison of the repaired car, or the diminished-value gap will be distorted.
Is this an insurance offer?
No. This page is an educational 17c estimate for vehicles in the United States. It does not bind an insurer, set a legal award, or replace an appraisal. Carriers, appraisers, and courts can use other methods, and state law decides whether diminished value is payable at all. A real claim still needs the repair estimate, photos, and proof of the pre-loss value. Comparable sales or a written appraisal are what usually move an offer above the 17c worksheet.