Comparative Fault Calculator
Enter your claim value, your percentage of fault and your state to see what your state's comparative or contributory negligence rule would do to your recovery.
How this calculator works
The calculator applies your state's general-negligence comparative or contributory fault rule — the same classifications from our comparative negligence by state guide — to the claim value and fault percentage you enter:
- Pure comparative negligence: your claim value is reduced by your fault percentage, at any percentage.
- Modified comparative negligence (50% or 51% bar): the same reduction applies, but recovery is barred entirely once your fault reaches the state's threshold.
- Pure contributory negligence: any fault at all bars recovery, subject to narrow exceptions this calculator cannot evaluate.
The one number this calculator cannot give you is your actual fault percentage — that is determined by evidence and negotiation, not a slider. See our guide on what to do after a car accident for how to preserve the evidence that decides it, and our demand letter generator when you are ready to open negotiations.
Frequently Asked Questions
How accurate is this fault calculator?
It applies the general negligence fault rule for the state you select — the same classifications from our comparative negligence by state guide — to the claim value and fault percentage you enter. It cannot account for claim-type variations, gross-negligence exceptions, or how a real adjuster or jury would actually assign your fault percentage. Treat the result as a reference to discuss with a licensed attorney, not a settlement figure.
Who decides my percentage of fault?
Ultimately a judge or jury, if the case is litigated — but in practice, most claims settle based on a percentage negotiated between your attorney and the insurance adjuster, informed by police reports, witness statements and physical evidence. Insurers frequently open with a higher fault percentage against you than the evidence supports.
Why does South Dakota show a different kind of result?
South Dakota uses a "slight-gross" standard instead of a percentage-based rule: you can recover only if your own fault was slight compared to the defendant's, which was gross. That comparison cannot be reduced to a percentage threshold, so this calculator does not compute a number for South Dakota — it flags the state as a special case instead.
Does this calculator account for Michigan's economic-damages exception?
No — it shows the simplified full-claim result used elsewhere on this site. In Michigan specifically, the 51% bar applies only to non-economic damages (pain and suffering); economic damages such as medical bills and lost income are typically still recoverable, reduced by your fault percentage, even above 50% fault. If you select Michigan, read the note above the result before relying on it.