Why the deadline is harder than the arithmetic
A statute of limitations gives you a fixed window to file a claim. Miss it and the claim is normally dismissed however strong it is, because limitation is an affirmative defence that courts enforce regardless of the merits. The rationale is that evidence decays, memories fade and defendants should not face open-ended exposure.
Adding a period to a date is trivial. The difficulty is entirely in the three inputs. When did the claim accrue? Usually the date of injury or breach, but not always: a continuing violation may accrue afresh with each act, and an instalment contract may accrue separately on each missed payment. Was the clock ever stopped? A claimant who was a minor or legally incapacitated, a defendant who left the jurisdiction, fraudulent concealment of the claim, and a written standstill agreement can all toll the period, sometimes for years. Did the period start at accrual at all? Under a discovery rule the period runs from the point you knew or reasonably should have known of the injury and its cause, which for latent injuries and professional negligence can be far later than the act itself.
This calculator keeps those three separate and works in days from accrual, so you can see exactly what each one is worth. Convert the answer to a calendar date by counting the deadline figure forward from your accrual date.
The four terms, and the trap that sits behind two of them
The period itself comes from the statute for your claim type and jurisdiction. Personal injury, contract, fraud, defamation and claims against public entities frequently have different periods in the same state, and choosing the wrong one is the most common way to get this wrong before any arithmetic starts.
The discovery rule moves the start date rather than lengthening the period. That distinction matters for a reason many people miss: nearly every state pairs a discovery rule with a statute of repose, an absolute outer limit measured from the defendant's act rather than from the plaintiff's knowledge. A repose period cannot be extended by discovery and usually cannot be tolled at all, and it can extinguish a claim before the plaintiff has any way of knowing it exists. Construction defects and product liability are the classic settings. This calculator does not model repose, so if your claim type has one, treat that date as a hard ceiling on everything computed here.
Tolling adds days to the end. Its most common form is minority: in most states a claim belonging to a child does not begin running until the child turns eighteen, which can push a filing deadline decades past the injury. Incapacity, a defendant's absence from the jurisdiction, active concealment of the facts, and a written standstill agreement are the other regular sources. All of them have to be proved, which is why the field on this page is a manual entry rather than something the calculator infers.
The roll-forward handles the last day landing badly. Under Federal Rule of Civil Procedure 6(a)(1)(C) and its state equivalents, when the last day of a period falls on a Saturday, Sunday or legal holiday, the period continues to the next day that is not one of those. Since this page works in day counts rather than in calendar dates, it cannot see which weekday the deadline falls on, so the roll is an explicit input. Add one to three days once you know the calendar date — and never rely on it, because a roll-forward that turns out not to apply costs you the case.
Worked example: a two-year period discovered late, with tolling
The claim accrued 120 days ago. The limitation period is two years. You did not discover the injury for 60 days after the event, and your jurisdiction applies a discovery rule to this claim type. A written standstill agreement with the defendant tolled the period for 90 days. The defendant is a public entity with a 180-day notice-of-claim requirement.
- Convert the period. Two years at 365.25 days a year is 730.5 days.
- Start from discovery. The period begins 60 days after accrual, so the base deadline sits at 60 + 730.5 = 790.5 days from accrual.
- Add the tolling. 790.5 + 90 = 880.5 days from accrual.
- Subtract what has gone. 880.5 − 120 = 760.5 days remaining, which is 760.5 ÷ 30.4375 = 24.99 months.
- Share of the window used. 120 ÷ 880.5 = 13.63%.
- The notice deadline. 180 − 120 = 60 days remaining, and this one is the binding constraint.
That last line is the point of the example. There are two years and a month left on the limitation period and two months left on the notice requirement, and a claimant watching the limitation date will lose the claim without ever coming close to it. Notice-of-claim statutes are short by design, they apply to claims against cities, counties, school districts, transit authorities and state agencies, and courts enforce them strictly. Without the discovery rule and the tolling, the same facts would give a deadline at day 730.5 and 610.5 days remaining — the two adjustments are worth 150 days between them.
How to read the result
Treat the days-remaining figure as shorter than it looks. Filing is not the last step: a complaint has to be drafted on facts you can plead, the defendant has to be identified and served within a separate deadline, and a defect discovered in the last fortnight often cannot be cured before the period expires. Practitioners work to an internal deadline well ahead of the statutory one for exactly this reason.
Watch the share-of-window figure over time rather than the raw day count. It answers a different question: how much of the runway is gone. A claim at 90% elapsed needs a decision now even if the absolute number of days sounds comfortable, because the remaining work does not shrink as the window does.
Then check every assumption that produced the number, because each is a legal judgement rather than a fact. If the discovery rule turns out not to apply to your claim type, the deadline moves earlier by the whole discovery delay — on the default figures, from day 880.5 to day 820.5. If the tolling cannot be established, it moves earlier again by the tolling days. The calculator will happily compute a comfortable answer from two assumptions that a court rejects, and the failure mode is not a smaller recovery but no claim at all.
Finally, remember what is not modelled: the statute of repose, any claim-specific accrual rule, differences between the deadline for filing and the deadline for serving, and the possibility that different claims arising from the same facts carry different periods. It is common for a single incident to support a negligence claim with a two-year period and a contract claim with a much longer one.
Typical limitation periods by claim type
| Claim type | Common range | What usually starts the clock |
|---|---|---|
| Personal injury | 1 to 3 years | Date of injury |
| Medical malpractice | 1 to 3 years, with a repose ceiling | Discovery of the injury, capped by repose from the act |
| Written contract | 3 to 6 years | Date of breach |
| Oral contract | 2 to 4 years | Date of breach |
| Fraud | 2 to 6 years | Discovery of the fraud |
| Property damage | 2 to 6 years | Date of damage |
| Defamation | 1 to 2 years | Date of publication |
| Claims against a public entity | Notice in 30 to 180 days, then a short suit period | Date of injury |
Every row varies by state, and several states apply different periods to sub-categories within a row. Use the table to see the shape of the landscape, then read your own statute.
How filing deadlines get missed
- Using the wrong accrual date. The date of the accident, the date of diagnosis and the date the last payment was missed can be months or years apart, and only one of them is right for your claim.
- Assuming the discovery rule applies. It is claim-specific and state-specific, and even where it applies it is limited by a statute of repose that cannot be extended.
- Missing the notice-of-claim deadline. Against a public entity this can be as short as thirty days, and missing it bars the claim even though the limitation period runs for years.
- Relying on tolling you cannot prove. Tolling is a fact question. An oral agreement to hold off, or an assumption that a defendant's absence counted, is not a defence to a late filing.
- Forgetting the service deadline. Filing within the period is necessary and not sufficient; the defendant must also be served within the time the rules allow, and dismissal for late service can leave the claim time-barred.
- Applying one period to every claim in the case. A single set of facts often supports claims with different periods. The shortest one governs that claim, not the whole case.
What happens on either side of the deadline
Before the deadline, the question is whether the claim is worth bringing. The litigation expected value calculator weighs a settlement offer against the probability-weighted value of proceeding, and the personal injury settlement calculator builds a claim value from medical specials and general damages. If comparative fault is in play, the comparative negligence calculator shows how the three rules in use change the recovery, and in a contributory-negligence jurisdiction it can eliminate it entirely.
After a judgment, the clock starts again in a different form: judgments have their own enforcement lifespan, usually renewable if you file before it lapses, and they accrue interest at a statutory rate in the meantime. The judgment interest calculator covers both the accrual and the daily figure a payoff demand has to state.
On the recovery side, the contingency fee net settlement calculator shows what a gross figure actually leaves after the fee, the case costs and any medical liens. And if you are counting days for other purposes, the age in days calculator and the day of week calculator convert between dates and counts — the second is the quickest way to find out whether your computed deadline lands on a weekend and therefore needs the roll-forward field on this page.
A missed deadline is not recoverable
Almost every other mistake in a case can be fixed. A late filing usually cannot. Limitation is raised on a motion to dismiss, decided on the pleadings, and does not consider how strong the claim was. If your figure here is anywhere near zero, or if it depends on a discovery rule or a tolling argument that has not been confirmed, treat that as a reason to speak to a lawyer today rather than as a calculation to refine. Nothing on this page is legal advice, and the periods and doctrines described vary by jurisdiction.