Diminished Value Calculator
Estimate the loss of value your car suffered after an accident using the standard 17c formula.
Built for general U.S. informational use. Local rules, court practices, and case facts can change the result.
Diminished Value Calculator
Fill in the fields below to get your estimate
How Does a Diminished Value Calculator Work?
Our tool uses the standard 17c Formula, which is widely adopted by insurance companies to estimate loss of value after a collision. The formula starts with a base loss (capped at 10% of the vehicle's pre-accident value) and reduces it based on two main factors: Damage Severity and Mileage.
The 17c Formula Mechanics
- Base Loss of Value: 10% of your car's Kelley Blue Book (KBB) or NADA clean retail value before the crash.
- Damage Multiplier: Ranges from 1.00 (severe structural damage) down to 0.00 (no structural damage/minor cosmetic).
- Mileage Multiplier: High mileage reduces the diminished value claim. Ranges from 1.00 (under 20k miles) down to 0.00 (over 100k miles).
The 17c formula often results in lowball offers from insurance companies. If your vehicle is brand new or a high-end luxury car, consider hiring an independent diminished value appraiser to get a more accurate (and usually higher) assessment.
How this estimate works
This calculator uses a 17c-style diminished-value framework to estimate post-accident vehicle value loss. It is a negotiation shortcut and may differ from an appraisal, insurer method, or state-specific claim rule.
Inputs this page weighs
- Pre-accident vehicle value.
- Damage severity.
- Mileage modifier.
- Repair quality and prior damage.
How to verify the result
Compare the result with repair invoices, vehicle-history reports, comparable sales, and any insurer or appraisal requirements.
How to use this Diminished Value Calculator well
Best used when
- Creating a starting point for a post-accident diminished-value claim.
- Comparing a 17c-style estimate with your own pre-loss and repair records.
- Preparing for insurer discussion or an appraisal review.
Be careful if
- Some states, insurers, and appraisal contexts treat diminished-value claims differently.
- Mileage, pre-existing damage, and repair quality can move the estimate a lot.
- The 17c framework is a negotiating shortcut, not a universal rule of value.
Questions to answer next
- What was the vehicle worth immediately before the accident?
- Do you have repair invoices and evidence about residual stigma or condition?
- Would an independent appraisal better support the claim than a formula alone?
Before you use a financial damages calculator
What to gather first
- Medical bills, repair invoices, payroll records, insurance information, and receipts.
- Photos, incident reports, and any correspondence that helps explain fault or value.
- A list of future costs you expect, with notes about where each number came from.
Why results may change
- Policy limits, comparative fault, tax treatment, and evidence quality can change the value dramatically.
- Some formulas are only rough starting points and do not reflect negotiation leverage or venue risk.
- Large numbers often need supporting records, expert input, or independent valuations.
Best next step
- Keep the calculator output with the documents you used so you can explain the assumptions later.
- Mark which inputs are proven and which ones are only estimates.
- Use the result to prepare questions for an attorney, adjuster, or accountant before taking action.