Diminished Value Claim Calculator
The car, the damage and the 17c tables
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Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- General mathematical model
- Scope and limitations
- Educational estimate only. Confirm the assumptions, current rules, fees, and rounding that apply to your situation before making a decision.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter the car's market value just before the accident, the repair cost and the odometer mileage.
- 02
Pick the damage level for the headline, from 1 for severe structural damage to 5 for no structural damage. All five levels are priced in the table either way.
- 03
If you have a written quote for what the car is worth now it is repaired, from a dealer or an independent appraiser, enter it in the advanced options. It is the strongest cross-check on the page.
- 04
Leave the 17c tables alone unless you have a reason to change them: the 10% cap, the damage multipliers and the mileage multipliers are the method's own constants, and each label says what it is.
- 05
Read the 17c figure beside the real-world range of 10% to 20% of the repair bill, then the table: the 17c result at every damage level and every mileage band on your car's value.
Formula
17c diminished value = pre-accident value × 10% × damage multiplier × mileage multiplier. Damage multipliers: 1.00 severe structural damage, 0.75 major damage to structure and panels, 0.50 moderate, 0.25 minor structural damage, 0.00 no structural damage. Mileage multipliers in 20,000-mile bands: 1.00 under 20,000, 0.80 from 20,000 to 39,999, 0.60 from 40,000, 0.40 from 60,000, 0.20 from 80,000 to 99,999, and 0 at 100,000 or more. The cross-checks: real-world range = repair cost × 10% to 20%; market-based loss = pre-accident value − a post-repair quote.
Example
A car worth $30,000 before the accident, repaired for $7,500 after moderate damage to its structure and panels, with 32,000 miles on the odometer. 17c starts at 10% of value, $3,000, then multiplies by 0.50 for moderate damage and 0.80 for the 20,000 to 39,999 mileage band: $1,200, which is 4.0% of the car's value and 16.0% of the repair bill. The real-world range of 10% to 20% of the repair runs from $750 to $1,500, so 17c lands inside it. A dealer who values the repaired car at $27,000 shows a $3,000 loss, $1,800 above 17c. Had the damage been severe and structural, 17c would give $2,400; at 105,000 miles it gives $0 at every damage level.
Definitions
- Diminished value
- The resale value a car loses because it has an accident history, even after a full repair.
- 17c formula
- A diminished value method named after a paragraph of a court order in Georgia's Mabry litigation: 10% of value × a damage multiplier × a mileage multiplier.
- First-party claim
- A claim against your own insurance policy. Diminished value is clearly recoverable this way only in Georgia.
- Third-party claim
- A claim against the at-fault driver's liability insurance. Diminished value is recoverable this way in many states.
- Post-repair appraisal
- An independent valuation of the repaired car, compared with its pre-accident value, which measures the loss directly rather than by formula.
Good to know
Why a repaired car is worth less
Imagine two identical cars for sale at the same price, same year, trim, color and mileage, and one of them was in a crash and properly repaired. Almost every buyer picks the other one, and to sell the repaired car its owner has to cut the price. That price cut is diminished value: the resale value a car loses because it has an accident history, even when the repair restored its appearance and function. A 2023 paper in the NAIC's Journal of Insurance Regulation opens with almost exactly that illustration. The loss is real because it is recorded. Vehicle history services such as CARFAX and AutoCheck, and the insurer databases C.L.U.E. and A-PLUS, tie claims and repairs to a car's VIN, and dealers check them before making a trade-in offer. The same paper describes a repaired car that a dealer refused to take in trade at any price once a database showed the earlier damage. Repair quality matters too: sound structural work reduces the perceived loss, and poor work increases it. There are serious arguments against paying for it, and the paper sets them out. One is that the loss does not happen until the car is sold, so an owner who keeps the car for ten years never suffers it. Another is that paying these claims raises claim costs, and so premiums, for everyone. Those arguments are a large part of why the law is so uneven from state to state. Diminished value is also distinct from ordinary depreciation, which every car suffers with age and mileage whether or not it is ever damaged; the car depreciation page draws that curve. This page prices only the extra step down an accident adds on top of it, and it measures that step three ways: the 17c formula, a share of the repair bill, and a market quote for the repaired car when you have one.
Where 17c came from, and what the court actually held
The formula takes its name from Georgia, the state that has gone furthest in making insurers pay for diminished value. Georgia law had recognized the principle for decades, but according to the 2023 NAIC paper most insurers did not acknowledge or pay such claims before 2001 except in unusual circumstances. Then, on November 28, 2001, the Supreme Court of Georgia decided State Farm Mutual Automobile Insurance Co. v. Mabry, 274 Ga. 498, 556 S.E.2d 114. The court held that State Farm's policies obligated it to compensate policyholders for the loss of value a car suffers from physical damage, notwithstanding repairs that return it to its pre-loss condition in appearance and function, and that State Farm must assess that element of loss along with physical damage whenever a policyholder makes a general claim of loss. What the court did not do matters as much as what it did. The Supreme Court's opinion did not approve or prescribe any formula. It noted that State Farm had no methodology for assessing the loss and required it to use an appropriate one. The method now called 17c takes its name from a paragraph of an order entered by the lower court in the same litigation, and insurers commonly apply it. So when an adjuster presents 17c as the standard, precision helps: it is a convention with a court case in its history, not a formula that any appellate opinion wrote. The method itself is short. Take 10% of the car's value before the accident, which the NAIC paper describes as its retail value from a pricing guide. Multiply by a damage multiplier from 1.00 for severe structural damage down to 0.00 for none, and by a mileage multiplier that falls from 1.00 toward zero as the odometer climbs. On a $30,000 car with moderate damage at 32,000 miles, that is $3,000 × 0.50 × 0.80 = $1,200.
The case against 17c
17c is easy to apply, which is most of its appeal, and the criticism of it is specific. The 2023 NAIC journal paper, written by an insurance professor and two collision safety consultants, concludes that Georgia's 17c formula is neither sound nor well received. Its first objection is mileage. The formula starts from a retail value, and a retail value already reflects the car's mileage, so applying a separate mileage multiplier on top is seen by some as a double penalty. Its second is that the method never looks at the car: there is no post-repair inspection, so a flawless repair and a poor one score the same. Other features push in the same direction. The loss starts from a flat 10% of value whatever the car, so a vehicle whose buyers care intensely about accident history is treated like any other. The mileage multiplier drops by 0.20 every 20,000 miles and reaches zero at 100,000, so a car with 105,000 miles scores $0 at every damage level however bad the crash. And the damage multipliers ask someone to choose a category, which is itself a judgment. The mileage bands on this page, 1.00, 0.80, 0.60, 0.40 and 0.20 in 20,000-mile steps, follow the table diminished value appraisers publish; the band width is a field because no primary source fixes the edges. The cross-check on the page comes from the same paper, which quotes a licensed claims adjuster: in real-world settlements, diminished value tends to end up around 10% to 20% of the direct physical damage. On the defaults that range runs from $750 to $1,500 on a $7,500 repair, and the $1,200 17c figure lands inside it. Change the damage level or the mileage and it often does not. When 17c falls well below that range, the gap is the argument for gathering market evidence rather than accepting the formula.
Who can claim it, and how to show the loss
Whether anyone will pay diminished value depends less on the formula than on who you are claiming from. A first-party claim is against your own policy, and there the standard auto policy's limit of liability, the lesser of actual cash value or the cost of repair, is the obstacle. The 2023 NAIC paper finds Georgia the only state with clear legal direction that first-party claimants can recover diminished value from their own insurer. Courts elsewhere have split, and several, including in Florida, Texas, California, Maine and Delaware, have read the standard policy as not covering it; insurers can also add an endorsement that excludes it. A third-party claim is different. It is a claim against the at-fault driver, paid from that driver's property damage liability coverage, and it rests on the ordinary law of damages rather than on a policy's wording. The paper, drawing on a 2022 state-by-state survey by the law firm Matthiesen, Wickert & Lehrer, lists many states that allow diminished value in a third-party claim, including Arizona, Colorado, Florida, Georgia, Illinois, Indiana, Iowa, Louisiana, Maryland, New Mexico, New York, Oregon, South Carolina and Virginia, and a Connecticut court awarded it for a damaged vintage Corvette. Rules on proof and deadlines vary by state, and the claimant carries the burden of showing the loss. This is general information, not legal advice. Evidence is what moves these claims. The most persuasive is a written trade-in or purchase offer for the car before the accident and another after the repair, or an independent appraiser's report comparing the two. On the defaults, a dealer valuing the repaired $30,000 car at $27,000 shows a $3,000 loss, $1,800 more than 17c. Claims this size often suit small claims court, where the paper notes lawyers are rarely involved. And if the repair bill approaches the car's value, check first whether the car should have been totaled instead.
Frequently asked questions
How is diminished value calculated with the 17c formula?
Start at 10% of the car's pre-accident value, multiply by a damage multiplier from 1.00 for severe structural damage down to 0.00 for none, then by a mileage multiplier from 1.00 under 20,000 miles down to 0.20 from 80,000 to 99,999, and 0 at 100,000 or more. On a $30,000 car with moderate damage at 32,000 miles: $30,000 × 10% = $3,000, × 0.50 = $1,500, × 0.80 = $1,200.
Where does the 17c formula come from?
From Georgia. In State Farm Mutual Automobile Insurance Co. v. Mabry, decided November 28, 2001 (274 Ga. 498, 556 S.E.2d 114), the Supreme Court of Georgia held that State Farm's policies obligated it to pay for the value a car loses even after repairs, and to assess that loss when a policyholder makes a claim. The Supreme Court did not write a formula; it required an appropriate method. 17c takes its name from a paragraph of the lower court's order in that litigation.
Is the 17c formula fair?
It is widely criticized, and by claimants usually as too low. A 2023 paper in the NAIC's Journal of Insurance Regulation concludes it is neither sound nor well received: it applies a mileage multiplier to a retail value that already reflects mileage, which some see as a double penalty, and it never inspects the repaired car. It also starts from a flat 10% of value whatever the car, and gives nothing at all from 100,000 miles.
Can I file a diminished value claim with my own insurance company?
Clearly, only in Georgia. The same 2023 paper finds Georgia the only state with clear legal direction that first-party claimants can recover diminished value from their own insurer; courts elsewhere have split, and several, including in Florida, Texas, California, Maine and Delaware, have held that a standard policy does not cover it. Against the at-fault driver's insurer — a third-party claim — recovery is allowed in many states, including Arizona, Colorado, Florida, Georgia, Illinois, Indiana, Iowa, Louisiana, Maryland, New Mexico, New York, Oregon, South Carolina and Virginia. This is general information, not legal advice; rules and deadlines vary by state.
How much is a typical diminished value settlement?
There is no official figure. A claims adjuster quoted in the 2023 NAIC journal paper put real-world settlements at about 10% to 20% of the direct physical damage — $750 to $1,500 on a $7,500 repair. On the defaults here the 17c figure, $1,200, falls inside that range, while a dealer quote of $27,000 on a $30,000 car shows a $3,000 loss, $1,800 more than 17c.
Why does 17c give $0 for my high-mileage car?
Because the formula's mileage multiplier drops to zero at 100,000 miles, whatever the damage. On the default car at 105,000 miles, every damage level returns $0. That is a cut-off in the method, not evidence that the car lost nothing; a written trade-in quote or an independent appraisal is the way to show a real loss.
What evidence helps a diminished value claim?
Market evidence. Vehicle history services such as CARFAX and AutoCheck, and insurer databases such as C.L.U.E. and A-PLUS, record claims and repairs against the VIN, and dealers check them. A written trade-in offer from before and after the accident, or an independent appraiser's report, shows the loss directly rather than by formula.