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Diminished value and your history report
The record is what makes the loss permanent. A history report entry follows the car into every future sale, and no formula reads it.
A repaired car loses value because the accident is on a record the next buyer pulls, not because the repair was poor. That is why the loss survives a perfect repair, and why it is measured by comparing cars that carry a record against cars that do not.
A VIN-level value that already prices in a car's history tells you what a car with that record might sell for. It does not tell you the gap between that and the same car without the record, which is the thing a diminished value claim is about. The calculator below runs the insurer's formula, which ignores the record entirely.
What the formula produces
Enter a value and an odometer reading to see the number.
The formula never looks at your car's market.
It ignores what comparable vehicles with an accident on record actually list for, what was replaced versus repaired, and any written offer you already hold. Our free estimate uses those, and shows you both numbers side by side.
Calculate My Value LossFree, about 2 minutes, no account.
What an entry on the report changes
Three things, in order of how much they cost you. A buyer who sees an accident discounts before inspecting anything. A dealer taking the car in trade prices the same discount in, and often more, because they have to sell it on with the entry attached. And a structural repair narrows the pool of buyers who will consider it at all.
None of that is about repair quality, which is the part owners find hardest to accept. A flawless repair and a visible record produce a lower price than an invisible dent would have.
Whether it shows yet matters
History reports are populated from reports filed by others — insurers, shops, police, state agencies — so an accident sometimes has not appeared when an owner starts a claim. Our own method treats that as a real factor: if the market cannot see the accident yet, it has not reacted to it, and the estimate is lower.
It usually appears later, which is why a claim made before the entry shows is not a claim about a loss that never happened.
The formula reads none of this
The insurer's 17c calculation takes three inputs — pre-accident value, damage severity, mileage — and no more. Whether the accident is on record, what was replaced against repaired, and what comparable cars are actually listed at do not enter it.
That is the gap our estimate measures instead, using the repair-cost ratio as its starting point: a repair worth about 5% of the car's value starts near a 4% loss, about 10% near 6%, about 20% near 9%, about 30% near 12%, then moving for severity, structural work, age, mileage, repair quality and whether the record is visible yet. The full method and its limits are published.
Questions
Does a Carfax report reduce my car's value?
The accident does, and the report is how buyers find out about it. An entry on a vehicle history report is visible to every future buyer and dealer, and it is the reason a properly repaired car still sells for less than the same car with a clean record.
Is there a Carfax diminished value calculator?
A history-based value prices a specific vehicle taking its record into account, which is a different thing from measuring the loss that record caused. The loss is the gap between cars carrying a record and cars without one, and the calculator on this page shows what the insurer's formula produces, which ignores the record entirely.
The accident is not on my history report yet. Do I still have a claim?
The claim is about the loss in value, and reported accidents usually appear on the record in time. Our method does treat current visibility as a factor and returns a lower estimate while the market cannot see the accident, which is one of the reasons the estimate explains itself rather than just returning a number.
Can I get an accident removed from the record?
Not by us, and not as part of a diminished value claim. History report providers have their own dispute processes for genuinely inaccurate entries, and an accident that happened is not an inaccuracy.
Does it matter that the repair was done properly?
It matters to safety and to what the car is worth on inspection. It does not remove the record, and the record is what the next buyer prices. A well-repaired car with a visible accident still sells below a clean equivalent.
Read next
- Value after an accident — What actually moves the number.
- Choosing comparables — How the gap is measured properly.
- Our method — Coefficients, caps and limits.
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This is an estimate, not an appraisal or a promise of payment. It's based on the information you entered and general market data. Insurers may dispute or deny claims. Read the full disclaimer.