Appraisal guide · Compare
Appraisal vs dealer letter vs calculator
A calculator gives a rough figure in seconds and is useful only for deciding whether a claim is worth your time. A dealer letter is one buyer’s opinion of what the accident costs at trade-in. An independent appraisal measures the loss against comparable vehicles and explains every step. Insurers and courts give the most weight to evidence they can check.
By the Autoloss team · Reviewed by Monica Fisher · Published
The four options compared
| Evidence | What it is based on | Typical cost | Best used for |
| Online calculator | A percentage of the vehicle’s value | Free | A first check on whether to go further |
| Insurer formula (17c) | A 10% cap reduced by damage and mileage multipliers | None to you | Understanding the insurer’s offer |
| Dealer letter | One dealer’s view of trade-in value with the accident history | Often free | Supporting evidence |
| Independent appraisal | Comparable vehicles with and without accident history, plus your repair records | $250–$350 typical | The claim itself |
Online calculators
A calculator applies a simple percentage to the vehicle’s value. It cannot see your trim, your market, where the damage was or how it was repaired. Use it to judge scale. Our own rough estimate calculator says the same thing on the page: it is not a figure to send to an insurer.
The insurer’s formula
Some insurers answer a diminished value claim with a formula result. It is quick for them and it is not a market valuation. If your offer came from one, ask for the calculation in writing. Our guide to the 17c formula shows how the number is produced.
Dealer letters
A dealer letter states what a dealership would offer for your vehicle with its accident history, sometimes against what it would have offered without one. It has real strengths: a dealer buys vehicles every day, and the letter costs little or nothing.
Its limits are what an adjuster will point to:
- It is one buyer’s opinion, usually a sentence or two, with no comparable vehicles behind it.
- It speaks to wholesale or trade-in value, which is not the same as market value.
- The dealer has not reviewed the repair records.
- The writer is rarely available to explain the figure if the insurer questions it.
A dealer letter works best as supporting evidence next to a full valuation.
Independent appraisals
An appraisal identifies the vehicle precisely, reviews the repair invoice and photos, establishes the pre-loss market value from comparable vehicles, establishes the post-repair value from comparable vehicles with accident history, and explains the difference. The reader can follow each adjustment and check each comparable. That is what makes it harder to dismiss.
What our report contains is listed on the diminished value appraisals page, and how it is built is in our methodology.
Which one do you need?
- Deciding whether to bother: a calculator, then the eligibility checklist.
- A small loss on an older vehicle: a dealer letter and your own comparables may be proportionate. See doing it yourself.
- A meaningful loss, a disputed claim or a court filing: an independent appraisal.
Common questions
Will an insurer accept a dealer letter?
Some will consider it, and some will discount it because it has no comparable vehicles or method behind it. It is stronger alongside an appraisal than on its own.
Can I send the insurer a calculator result?
You can, but it carries little weight. A calculator applies one percentage and does not look at your vehicle, your repairs or your market.
Can I use more than one kind of evidence?
Yes. An appraisal supported by a dealer letter and your repair records gives the adjuster several consistent sources to weigh.
Keep reading
More from the appraisal guide
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How to choose a diminished value appraiser
Seven things to check, the questions to ask, and the warning signs.
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What a diminished value demand letter should include
The seven things it should contain, and the mistakes that weaken it.
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Does a diminished value appraisal need an in-person inspection?
What records and photos already show, and when an inspection adds something.
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Using a diminished value appraisal in small claims court
When it fits, what to bring, and what to ask the clerk first.
Not sure whether an appraisal will help?
The claim review is free: we look at your situation and tell you whether an appraisal is likely to help. The appraisal itself is a paid report. We help from start to finish, including a custom demand letter, and our support staff is a phone call away throughout the process.