Diminished Value Calculator

What Is Diminished Value?

Diminished value is the difference between:

• What your car was worth before the accident
• What it is worth after repairs, because it now has an accident history

Even high-quality repairs do not erase accident records. Buyers, dealers, and trade-in systems almost always pay less for a car that has been damaged before.

This loss is real. The challenge is proving it.

Why a Diminished Value Calculator Matters

Insurance companies rarely offer diminished value unless you ask. Even then, they usually start low.

A calculator helps you:

• Estimate your financial loss
• Understand how insurers think
• Set a realistic negotiation target
• Avoid guessing or relying on vague advice

It does not replace a professional appraisal, but it gives you a strong starting point.

The 17c Formula Explained Simply

Most insurance companies use a method called the 17c formula. Courts allowed it, and insurers adopted it as a standard.

The calculator you shared is based on this exact approach.

Here is the formula in plain terms:

Pre-accident value × 10% × damage modifier × mileage modifier

Each part matters.

Step 1: Pre-Accident Value

This is what your car was worth before the crash.

You can estimate it using:

• Market listings for similar cars
• Dealer appraisals
• Online pricing tools

In the calculator, this is entered as Pre-Accident Value ($).

Example:
If your car was worth $25,000, that is your starting point.

Step 2: The 10% Loss Cap

The 17c formula assumes that a car cannot lose more than 10% of its value due to diminished value.

So if your car was worth $25,000:

• Maximum base loss = $2,500

This cap is one reason many people say the 17c formula underestimates real-world loss. Still, it is what insurers rely on.

Step 3: Damage Severity Modifier

Not all damage is treated the same.

The calculator uses standard insurance multipliers:

• 1.00 – Severe structural damage
• 0.75 – Major structural or panel damage
• 0.50 – Moderate damage (default)
• 0.25 – Minor damage
• 0.00 – Cosmetic only

This value reduces the base loss depending on how serious the damage was.

If your base loss cap is $2,500 and your damage modifier is 0.50:

• Adjusted loss = $1,250

Step 4: Mileage Modifier

Mileage has a major impact on diminished value claims.

The calculator applies these rules:

• Under 20,000 miles: 0.80
• 20,000–39,999 miles: 0.60
• 40,000–59,999 miles: 0.40
• 60,000–79,999 miles: 0.20
• 80,000–99,999 miles: 0.00
• Over 100,000 miles: Automatic denial in most cases

If your car has 35,000 miles, the mileage modifier is 0.60.

Final Calculation Example

Let’s put it all together.

• Pre-accident value: $25,000
• 10% cap: $2,500
• Damage modifier: 0.50
• Mileage modifier: 0.60

Calculation:

• $2,500 × 0.50 × 0.60 = $750 diminished value

This is the 17c calculated loss shown by the calculator.

What the Calculator Also Gives You

This calculator does more than show one number.

1. Full Formula Breakdown

You see exactly how the result was calculated. This builds confidence when talking to an adjuster.

2. Mileage and Damage Multipliers

No hidden math. Everything is visible.

3. Negotiation Target Range

The calculator suggests a higher settlement range, usually 1.5x to 1.8x the 17c amount.

Why?
Because insurers often start low, and negotiation is expected.

4. Smart Claim Insight

Based on your inputs, the calculator explains whether:

• Your claim is strong
• Mileage may hurt your case
• Structural damage works in your favor

This guidance mirrors how real adjusters think.

How to Use the Result in Real Life

The number from a diminished value calculator is not a demand. It is leverage.

Here is how to use it well:

• Start negotiations near the suggested target range
• Expect pushback on mileage and damage severity
• Stay calm and factual
• Use written estimates and repair reports to support your claim

If the insurer offers only the base 17c amount, you now know why. You also know when that offer is weak.

Limits of Any Diminished Value Calculator

No calculator is perfect.

Keep these limits in mind:

• The 17c formula often undervalues luxury and newer cars
• Real market loss can be higher than the result
• State laws and insurer policies vary
• Cosmetic-only damage rarely succeeds

For large claims, a professional diminished value appraisal can still be worth it.

Who Benefits Most from This Calculator?

This tool is especially useful if:

• Your car is newer and low-mileage
• Structural or moderate damage occurred
• You plan to sell or trade the car later
• You want to negotiate confidently, not blindly

If your car has over 100,000 miles or only cosmetic damage, the calculator correctly warns that success is unlikely.