Diminished Value Calculator
Estimate the resale value a vehicle loses after an accident, using the insurance industry's 17c formula.
The 17c method
Applies the standard insurer formula: 10% base loss, scaled by damage and mileage.
An estimate, not an appraisal
17c often understates real losses — a professional appraisal carries more weight in a claim.
What is diminished value?
The price an accident leaves behind
Even after a flawless repair, a car that has been in an accident is worth less than one that hasn't. Buyers see the accident on the history report and pay less, worried about hidden damage and resale stigma. That gap is the diminished value. The 17c formula, named after a paragraph in a US insurance settlement, is the most common quick way to estimate it.
The formula starts from a base loss capped at 10 % of the car's value, then shrinks it with two multipliers.
DV = (market value × 10%) × damage multiplier × mileage multiplierThe damage multiplier runs from 1.00 (severe structural) down to 0.00 (none). The mileage multiplier is 1.00 below 20,000 miles and steps down to 0.00 at 100,000+. State insurance departments, such as California's, describe how insurers apply such formulas in diminished-value claims.
A car worth 20,000 before the crash has moderate, properly repaired damage and 30,000 miles.
Take the base loss
10 % of 20,000 is 2,000 — the capped base loss.Apply the damage multiplier
Moderate damage scores 0.50, giving 2,000 × 0.50 = 1,000.Apply the mileage multiplier
30,000 miles falls in the 0.80 band, giving 1,000 × 0.80 = 800.Read the result
The 17c diminished value is 800 — the resale value the repair did not restore.
17c is fast and consistent, but it has well-known limits.
Quick and standard
A single formula every insurer recognises — useful as a starting reference.
The 10% cap is arbitrary
Real losses on desirable models can exceed 10 % of value, which 17c never reaches.
Zeroes out at 100k miles
High-mileage cars get a diminished value of 0, even with serious damage — a common criticism.
For these reasons, many independent appraisers use market-based methods that compare real sale prices, which often produce higher figures than 17c.
The diminished value is the dollars the accident may have shaved off your car's resale price despite a good repair. The base loss, damage multiplier, and mileage multiplier are shown so you can see exactly how the number was built. Treat it as a floor for discussion, not a ceiling: because 17c is conservative, a market-based appraisal often supports a higher claim. If the figure is meaningful to you, the next step is usually an independent appraisal rather than submitting the formula result alone. It can also help to consult a financial advisor or insurance professional about whether pursuing the claim is worth the time and any appraisal fee, especially for an older or high-mileage vehicle where the 17c result is small or zero.
17c is a rule of thumb, and insurers know its weaknesses too.
Not a claim value or legal advice
This calculator reproduces the 17c formula for education and planning only. It does not reflect your specific vehicle, local market, or repair quality, and it is not legal or financial advice. Whether you can claim diminished value depends on fault and your jurisdiction. For an actual claim, obtain an independent diminished-value appraisal and check your state's rules and your policy; consult a professional before relying on any figure.