acalculator

What is my car’s diminished value?

Type your car’s value before the accident, how bad the damage was and its mileage. The diminished value calculator shows the loss by the 17c formula that many insurers use, and the value left after repair.

Your numbers

Mileage multiplier
Diminished value
$900.00

Diminished value by the 17c formula: $900.00 (10% base $3,000.00 × 0.5 × 0.6).

Base loss (10% cap)
$3,000.00
Damage multiplier
0.5
Mileage multiplier
0.6
Value after repair
$29,100.00

Diminished value: $900.00. Diminished value by the 17c formula: $900.00 (10% base $3,000.00 × 0.5 × 0.6).

The results are estimates for information only. They are not financial, tax, or legal advice. Check the numbers with your lender or a qualified professional before you decide. Terms of use

How to calculate

Estimates a car’s diminished value after an accident by the 17c formula: 10% of its pre-accident value, times a damage multiplier and a mileage multiplier.

Example with the default inputs (Value before the accident $30,000.00, Damage Moderate structural and panel damage (0.50), Mileage 45,000, Mileage multiplier 20,000-mile steps): Diminished value by the 17c formula: $900.00 (10% base $3,000.00 × 0.5 × 0.6).

Method: Diminished value = value before the accident × 10% × damage multiplier × mileage multiplier. Mileage multiplier in steps: 1 − 0.2 × (whole 20,000-mile steps), 0 from 100,000 miles; on a straight line: 1 − miles ÷ 100,000, 0 from 100,000 miles.

  • The 17c formula is an insurer’s method from a Georgia class-action settlement; it is not a law, and a market appraisal often finds a larger loss.
  • The value before the accident is the market value, which you look up and type.
  • Whether you can claim diminished value, and from whom, depends on your state and policy.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. Value before the accident $30,000.00, Damage Moderate structural and panel damage (0.50), Mileage 45,000, Mileage multiplier 20,000-mile steps gives Base loss (10% cap) $3,000.00, Mileage multiplier 0.6, Diminished value $900.00, Value after repair $29,100.00.Source: SnapClaim, Demystifying the Diminished Value 17c Calculator. https://snapclaim.com/diminished-value-17-c-calculator/ ($30,000 value, 10% = $3,000, moderate damage 0.50, 45,000 miles 0.60: $900)
  2. Value before the accident $21,100.00, Damage Moderate structural and panel damage (0.50), Mileage 43,000, Mileage multiplier Straight line gives Base loss (10% cap) $2,110.00, Mileage multiplier 0.57, Diminished value $601.35.Source: 17cformula.com, The 17c Formula (base loss 10% of value; damage modifiers 1.00 to 0.00; mileage modifiers 1.0 at 0 miles to 0.0 at 100,000+). https://17cformula.com/17c_diminished_value_formula_ebook.html (2010 MX-5 at 43,000 miles, $21,100: base $2,110, × 0.57, × 0.5 = $601, rounded)
  3. Value before the accident $150,000.00, Damage Major structural and panel damage (0.75), Mileage 25,000, Mileage multiplier 20,000-mile steps gives Base loss (10% cap) $15,000.00, Mileage multiplier 0.8, Diminished value $9,000.00.Source: SuperCar Claims, 17c Formula. https://www.supercarclaims.com/17c-formula/ ($150,000, base $15,000, damage 0.75, mileage 0.80: $9,000)
  4. Value before the accident $40,000.00, Damage Severe structural damage (1.00), Mileage 120,000, Mileage multiplier 20,000-mile steps gives Mileage multiplier 0, Diminished value $0.00, Value after repair $40,000.00.Source: 17cformula.com, The 17c Formula (base loss 10% of value; damage modifiers 1.00 to 0.00; mileage modifiers 1.0 at 0 miles to 0.0 at 100,000+). https://17cformula.com/17c_diminished_value_formula_ebook.html (100,000+ miles: modifier 0.0)

How it works

  • Base loss = value before the accident × 10%.
  • Damage multiplier: 1.00 severe structural damage; 0.75 major structural and panel damage; 0.50 moderate structural and panel damage; 0.25 minor structural and panel damage; 0.00 no structural damage (panels replaced).
  • Mileage multiplier, 20,000-mile steps: 1 − 0.2 × (miles ÷ 20,000 rounded down), so 1.0 below 20,000 miles, 0.8 from 20,000, 0.6 from 40,000, 0.4 from 60,000, 0.2 from 80,000, and 0 from 100,000 miles.
  • Mileage multiplier, straight line: 1 − miles ÷ 100,000, and 0 from 100,000 miles.
  • Diminished value = base loss × damage multiplier × mileage multiplier.
  • Value after repair = value before the accident − diminished value.

Every step is an exact fraction of the numbers you type; dollar outputs round once, half up, to the cent.

Assumptions

  • The value is from $0 to $1,000,000,000 and the mileage from 0 to 2,000,000 miles.
  • The 17c formula is an insurer method from a Georgia settlement, not a law or a market appraisal.
  • You look up the value before the accident (a pricing guide or an appraisal) and choose the damage level yourself.

Worked examples by hand

SnapClaim's example. $30,000 × 10% = $3,000; moderate damage 0.50; 45,000 miles in steps = 1 − 0.2 × 2 = 0.6; 3,000 × 0.5 × 0.6 = $900; value after repair $29,100.

The MX-5 at 43,000 miles, straight line (17cformula.com). $21,100 × 10% = $2,110; 1 − 43,000 ÷ 100,000 = 0.57; 2,110 × 0.57 × 0.5 = $601.35 (the source shows $601).

A $150,000 car (SuperCar Claims). Base $15,000; major damage 0.75; 25,000 miles = 0.8; 15,000 × 0.75 × 0.8 = $9,000.

120,000 miles. The mileage multiplier is 0, so the 17c diminished value is $0 whatever the damage.

Other questions people ask

What is diminished value?

It is the market value a car loses because it has been in an accident, even after a good repair. Buyers pay less for a car with an accident history, so the repaired car is worth less than the same car with no accident.

What is the 17c formula?

A formula from the 2001 Georgia class action State Farm v. Mabry, named after paragraph 17c of the settlement. It takes 10% of the car’s value before the accident as the most it can lose, then multiplies by a damage multiplier (1.00 to 0.00) and a mileage multiplier (1.0 to 0.0).

How do I calculate diminished value?

Multiply the value before the accident by 10%, then by the damage and mileage multipliers. A $30,000 car with moderate damage (0.50) and 45,000 miles (0.60) gives 3,000 × 0.50 × 0.60 = $900.

Which mileage multiplier is right?

Many 17c worksheets drop the multiplier by 0.2 at each 20,000 miles: 1.0 under 20,000, 0.8 under 40,000, 0.6 under 60,000, 0.4 under 80,000, 0.2 under 100,000 and 0 from there. Some interpolate on a straight line instead, so 43,000 miles gives 0.57. Choose the rule your insurer uses.

Is the 17c result what I will get?

Not always. The formula is an insurer method, not a law, and it caps the loss at 10% of the value. Critics point out that a market-based appraisal often finds a loss several times larger. You can dispute a low offer with an independent appraisal.

Can I claim diminished value?

It depends on your state and on who caused the accident. Claims against the at-fault driver’s insurer are the most common; a claim on your own policy is often excluded. Ask your insurer or your state insurance department.