About the Vehicle Diminished Value Calculator
When a car is damaged in an accident and repaired, it is usually worth less than an identical car with no accident history, even if the repair is excellent. Vehicle history reports record the accident, and buyers and dealers pay less for cars with a damage record. That loss is called diminished value, and in many places you can claim it from the at-fault driver's insurer in addition to the cost of repairs.
This vehicle diminished value calculator uses the 17c formula, the method many insurers use as a starting point. It takes the car's market value before the accident, applies a 10% cap, then adjusts for how severe the damage was and how many miles the car has done. It shows the estimated diminished value and the share of the car's value lost.
How to Use the Vehicle Diminished Value Calculator
Enter the car's pre-accident market value.
Choose the damage severity.
Enter the mileage at the time of the accident.
The Formula
base loss = pre-accident value × 10%
damage multiplier = 1.00 severe, 0.75 major, 0.50 moderate, 0.25 minor, 0 none
mileage multiplier = 1.0 under 20,000; 0.8 to 39,999; 0.6 to 59,999;
0.4 to 79,999; 0.2 to 99,999; 0 at 100,000+
diminished value = base loss × damage × mileageStep-by-Step Example
A car worth 25,000, moderate damage, 30,000 miles.
base loss 25,000 × 10% = 2,500
damage × 0.50 = 1,250
mileage × 0.8 = 1,000
share 1,000 ÷ 25,000 = 4%Where the 17c Formula Comes From
The formula takes its name from a Georgia class-action settlement in the early 2000s, in which an insurer agreed a standard way to calculate diminished value. Many insurers have since adopted it across the United States. It is simple and consistent, which is why insurers like it, but critics point out that the 10% cap and the steep mileage reductions often produce figures well below the real loss in the market.
Finding the Pre-Accident Value
Use the car's market value just before the accident, not what you paid for it. Online valuation guides, dealer appraisals and listings for similar cars with similar mileage and options all help. A higher starting value increases the diminished value, so it is worth documenting carefully with screenshots and listings.
Damage Severity
The damage multiplier reflects how much the accident affects buyers' perception. Damage to the frame or structure, airbag deployment and major panel replacement weigh most heavily. Cosmetic damage repaired without structural work counts least, and under 17c may give no diminished value at all. Repair estimates and photos showing the extent of the damage support the severity you claim.
Making a Stronger Claim
Because 17c often understates the loss, many owners gather more evidence: an independent diminished value appraisal, written trade-in offers from dealers comparing the car with and without its accident history, and listings showing how accident-damaged cars of the same model sell for less. Present these to the insurer with the repair invoice and vehicle history report. If the insurer will not agree, small claims court is an option in many places.
Who Can Claim
Diminished value claims are usually made against the at-fault driver's insurance. Claims against your own policy are limited or excluded in most states. Leased cars and financed cars may have special rules about who receives the payment. There are time limits, so act promptly after repairs are complete.
Types of Diminished Value
Three types are often described. Inherent diminished value is the loss in market value simply because the car now has an accident history, even after a perfect repair; it is what most claims are about. Repair-related diminished value arises when repairs are poor, such as mismatched paint or non-original parts. Immediate diminished value is the difference in value right after the accident, before any repair, and is mainly used in total loss discussions.
Newer and Luxury Cars
Diminished value matters most for newer, low-mileage and luxury vehicles, where an accident record can cut resale value sharply. A two-year-old premium car with structural damage may lose far more than the 17c formula's 10% cap suggests. For such cars, an independent appraisal is usually worth its cost.
Selling After an Accident
If you plan to sell or trade in the car soon after the accident, gather trade-in offers before and after the damage is recorded. The difference is direct evidence of diminished value. Keep all repair invoices, which help buyers trust the quality of the repair and may soften the price drop.
Keeping Records
Keep the police report, photographs of the damage, the repair estimate and final invoice, the vehicle history report and all correspondence with the insurer. A clear paper trail makes a diminished value claim far easier to support and settle.
Total Losses
If the insurer declares the car a total loss, diminished value does not apply; the payout is the car's market value instead.
Understanding Your Result
The headline gives the estimated diminished value.
The working line shows the base loss and the two multipliers.
The share of value line shows the loss as a percentage.
The making a claim line explains how to support a higher figure.
When Should You Use This Calculator?
Use it after an accident caused by another driver.
Use it to check an insurer's diminished value offer.
Use it to decide whether an independent appraisal is worthwhile.
Common Mistakes
Accepting the first offer. The 17c figure is a starting point.
Using the purchase price. Use the pre-accident market value.
Claiming on your own policy. Usually the at-fault insurer pays.
Waiting too long. Claims have deadlines.