Free tool · Tort Law
Comparative Negligence Calculator
When a plaintiff is partly at fault for their own injury, the result depends on the rule of the state. A few states still bar recovery completely (contributory negligence). Most compare fault: under pure comparative fault the plaintiff recovers their damages reduced by their share, while under modified comparative fault the plaintiff recovers only if they are less than 50% or no more than 50% at fault, depending on the state. Enter the damages and the shares of fault to see all four results side by side, and what happens if one defendant cannot pay.
Tool · Comparative Fault Calculator
50%
| Rule | Plaintiff recovers |
|---|---|
| Contributory negligence (a few states and DC). Any fault of the plaintiff, however small, bars recovery completely (with exceptions such as last clear chance). | $0 |
| Pure comparative fault. Recovery is reduced by the plaintiff’s share, however large (30%). | $70,000 |
| Modified comparative fault, 50% bar (the plaintiff may recover only if less at fault than the defendants). The plaintiff is less than 50% at fault, so recovers the reduced amount. | $70,000 |
| Modified comparative fault, 51% bar (the plaintiff may recover unless more than 50% at fault). The plaintiff is not more than 50% at fault, so recovers the reduced amount. | $70,000 |
Joint and several, or several only: Defendant B cannot pay its share of 50,000. Under joint and several liability the plaintiff can collect all of the defendants’ combined share (70,000) from A, who may seek contribution from B. Under several-only liability the plaintiff bears the risk and recovers only A’s own share (20,000).
States have chosen different rules, and many have changed them by statute. Many now limit joint and several liability, and some apply it only where the defendant was more than a stated share at fault. Check the rule in your state.
The same accident gives very different results under the rules that states have adopted for a plaintiff who was partly at fault: contributory negligence (a complete bar), pure comparative fault, and the two forms of modified comparative fault. The calculator also shows what happens when one of two defendants cannot pay, under joint and several liability and under several-only liability. Invented figures and simplified general rules; many states have changed these rules by statute. Not legal advice. Runs in your browser; nothing is stored or sent.
How to use it
- Enter the total damages.
- Enter the plaintiff’s share of fault and defendant A’s; defendant B takes the rest.
- Say whether defendant B can pay its share.
- Compare the four rules and the joint-and-several result.
Common questions
What is the difference between the 50% and 51% bar?
Under the ‘49% rule’ the plaintiff recovers only if less at fault than the defendants (under 50%). Under the ‘50% rule’ the plaintiff recovers if not more at fault than the defendants (50% or less). At exactly 50%, the first bars recovery and the second allows it.
What is joint and several liability?
Each defendant can be made to pay the whole of the damages that they share responsibility for, leaving them to seek contribution from the others. Many states have limited it so that each defendant pays only its own share.
Which states still use contributory negligence?
A small number of states and the District of Columbia. Rules have changed over time, so check the current law of the state.
Learn the law behind the tool
This tool is part of our Tort Law course, with lectures, concept maps, flashcards, interactive exercises and a capstone case. Tort Law: Damages, Defences and Strict Liability.
More free law tools
General information, simplified, mainly on American law, not legal advice. States and countries differ, and real cases turn on facts that a tool cannot capture.