When a contract runs late, the liquidated-damages clause turns delay into a defined, daily cost. This calculator multiplies the contractual rate by the delay period and applies any cap so contractors, project managers, and procurement teams can quantify exposure without re-reading the clause every time.
How it works
Damages accrue per unit of delay up to the contractual ceiling:
delay days = completion date − contractual date (calendar days)
daily rate = rate, or weekly rate / 7
accrued LDs = daily rate × delay days
total LDs = min(accrued LDs, cap) (if a cap is set)The cap is the critical limiter: once accrued damages reach the contractual maximum, further delay adds no liability, which changes the negotiating position materially.
Worked examples
Example 1 — Below the cap: A contract with £5,000 per day LDs and a £200,000 cap that finishes 30 days late accrues £150,000. This is below the cap, so the full £150,000 is due.
Example 2 — Cap reached: The same contract finishing 50 days late would arithmetically accrue £250,000, but the cap limits the recovery to £200,000. Once the cap is reached, the contractor has no additional LD liability regardless of further delay — though other contractual remedies such as termination may still apply.
Example 3 — Weekly rate: A subcontract specifies £25,000 per week rather than a daily figure. For a 9-day delay, the effective daily rate is £25,000 / 7 = £3,571.43, and the accrued LDs are £3,571.43 × 9 = £32,143. Where the contract specifies whole weeks only, the 9-day delay might be rounded to one complete week (£25,000) — check the clause wording.
Extensions of time and their effect
Before computing delay days, you must determine whether any extensions of time (EOTs) were properly granted. An EOT shifts the contractual completion date forward, reducing the delay period. Using the original completion date when an extension was agreed overstates the LD claim — a significant error in adjudication or litigation. Always adjust the start date in this calculator to reflect the last formally agreed EOT.
Common grounds for EOTs include: employer-instructed variations, late information from the employer, concurrent delays caused by the employer’s team, and excusable delays such as exceptionally adverse weather (where the contract provides for this). Disputed EOT entitlement is frequently the central issue in construction LD claims.
The legal enforceability question
A liquidated damages clause is enforceable in most jurisdictions if it represents a genuine pre-estimate of the loss the employer would suffer from delay — not a figure designed to punish or coerce. A clause that is extravagant or unconscionable relative to the likely loss may be struck down as a penalty, leaving the employer to prove actual loss (which is often harder and produces a different number).
In English law, the test was clarified in Cavendish Square v Makdessi (2015): the relevant question is whether the clause has a legitimate interest in performance and is not extravagant relative to that interest. Other jurisdictions apply similar but not identical tests. Take legal advice when the LD rate looks very high relative to the contract value, when the sum has not been reviewed against current loss levels since the contract was drafted, or when the other party is asserting unenforceability as a defence.
Always adjust the start date for any extensions of time first: counting from the original date when an extension was granted overstates the claim.