Delay damages calculator — NEC X7 and JCT LADs
Free, no sign-in. Nothing you type is stored or sent anywhere — it's all worked out in your browser.
Enter both completion dates and a valid rate.
Not legal or tax advice — check your contract. Your contract terms and the facts of your job can change the answer.
How this works
Calendar days late are the positive difference between the completion dates. A daily rate multiplies days late; a weekly rate uses days divided by seven, pro-rating part weeks. Check your contract if it charges started weeks instead.
NEC X7 specifies a rate per day. JCT liquidated damages rates are often weekly. A £ cap or percentage-of-contract-sum cap limits the result.
Sectional completion needs a separate calculation per section. This arithmetic does not decide entitlement, enforceability, extensions or notice compliance.
FAQs
Do weekends count?
Yes. This tool counts calendar days.
What about part weeks?
This calculator pro-rates them as days divided by seven. Check whether your contract instead charges started weeks.
What date should I enter?
The contractual Completion Date including extensions, not the unamended original date.
What about sectional completion?
Run a separate calculation for each section using its own date, rate and cap.
Civvio works this out automatically from your contract and site records.
Upload the contract and keep your diary, and Civvio flags the dates, notices and money at risk on every job — for you to review before anything is sent.
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