The 17c formula, explained
The 17c formula is associated with State Farm’s Georgia claim process: it starts with 10% of a vehicle value, then applies damage and mileage modifiers. The exact inputs matter, and the result is not a universal measure of actual loss.
The three steps
- Start with 10% of the chosen car value. In the calculation described by the court, later modifiers reduce this starting amount.
- Multiply by a damage factor.
- Multiply by a mileage factor.
A worked example
Suppose an insurer uses a $16,000 vehicle value, a 0.50 damage modifier and a 0.60 mileage modifier. These two modifiers are illustrative inputs, not a published schedule that applies to every claim:
$16,000 × 10% = $1,600 → × 0.50 = $800 → × 0.60 = $480.
Ask the insurer for its chosen vehicle value, damage category, mileage modifier and supporting explanation. A different version or different inputs can produce a different result.
What the calculation leaves open
- The starting point limits the result. A 10% base followed by modifiers of one or less cannot produce an amount greater than that base.
- Mileage may enter twice. If the starting vehicle value already reflects mileage, a separate mileage modifier reduces the result again. An article in the NAIC's Journal of Insurance Regulation discusses this criticism; it reflects its authors' views.
- Market evidence still matters. The formula by itself does not establish what your repaired vehicle would sell or trade for. Relevant comparables and the repair record can help test an offer.
Where it applies
The Georgia Supreme Court addressed State Farm’s duty to assess diminished value under the policy at issue in State Farm v. Mabry. A later unpublished, non-precedential federal appeals court opinion in Tiller v. State Farm describes State Farm’s use of a formula referenced in a 2002 Georgia trial court order. Neither opinion makes the example above a universal payment rule. See our Georgia and Florida guides for claim context.
Common questions
What is the 17c formula?
A calculation associated with State Farm’s Georgia diminished-value claims. It starts with 10% of a vehicle value and then applies damage and mileage modifiers. Actual claim procedures and modifiers may differ.
Is the 17c formula the law?
No. It is an insurer method associated with State Farm’s handling of claims after the Georgia Mabry litigation. The Georgia Supreme Court recognized diminished value in a first-party policy dispute; it did not make this formula a universal state-law measure.
Why might a 17c number be low?
In the version described by a federal appeals court, the 10% starting point and later modifiers can reduce the result substantially. Compare any offer with evidence about your own car and ask how the insurer reached it.
Can I dispute a 17c offer?
You can ask the insurer to review a documented valuation and explain its calculation. The applicable legal measure depends on your state, policy and claim type.
This page is general information, not legal advice about your situation. PriorWorth is not a law firm or a public adjuster and is not affiliated with any insurance company.