Project Delay Carrying-Cost Calculator
When a fit-out, a renovation or an occupancy certificate runs late, the cost is not one number. Put in the site costs that run only because the job runs longer, the money that carries interest while you wait and, if you want, the contribution you lose by opening later — the calculator keeps each one on its own line.
What this tool estimates
What a delay costs you while it lasts — avoidable site overhead, interest on the money tied up and any lost contribution you enter — each shown separately, with the cost per day of delay.
What it cannot decide
- How long the delay will be — you enter it.
- Whether any of it can be recovered from a contractor, landlord or anyone else. That depends on the contract and on who caused the delay; this is not a claim value.
- Whether your overhead figure already contains interest, or your lost contribution already contains overhead — you must keep them apart.
- Compounding, rate resets or further loan drawdowns during the delay.
Result
Count each rupee once. These lines add up only if the overhead figure contains no interest or financing charges, and the lost contribution contains neither overhead nor interest. Leave out costs you would have spent anyway.
This is your carrying cost, not a claim. Whether any of it is recoverable from a contractor, landlord or anyone else depends on the contract and on who caused the delay — see who an LD clause really punishes.
| Step | Value |
|---|
| Delay | Rate | Overhead + financing |
|---|
Method version 6 October 2026. A screening estimate, not a design: see the limits below.
How this calculator works — and where it stops
What it calculates
What a delay costs while it lasts: the site overhead that runs only because the job runs longer, the interest on the money tied up and — if entered — the contribution lost by opening or producing later, each shown on its own line, with the cost per day of delay.
Inputs
- Delay in calendar days.
- Avoidable site overhead per day, ₹ — costs that continue only because the job runs longer, with no interest in them.
- Amount carrying interest, ₹ — the drawn balance or capital actually tied up during the delay.
- Annual interest rate, % a year.
- Day basis, 365 or 360 — as the loan agreement counts interest; the tool does not assume one.
- Optional: contribution lost over the whole delay, ₹ — blank leaves it out.
Method
- Site overhead = delay days × avoidable site overhead per day.
- Financing = amount carrying interest × annual rate × delay days ÷ day basis — simple interest.
- Carrying cost = site overhead + financing.
- Cost of the delay = carrying cost + the lost contribution, when one is entered; when it is not, the result says so rather than counting it as ₹0.
- Per day of delay = overhead per day + amount × rate ÷ day basis.
- Sensitivity: overhead + financing at half and one-and-a-half times the delay and at the rate 2 points lower and higher, plus the financing on the other day basis.
Assumptions
- The overhead figure contains no interest, and the lost contribution contains neither overhead nor interest. The tool cannot check this: counting one cost in two lines overstates the delay.
- The amount is the balance that really carries interest through the delay — not the sanctioned limit or the project cost.
- Simple interest at a fixed rate; no compounding, rate resets or further drawdowns during the delay.
- Overhead and interest are both counted in calendar days.
Limitations
- Not a claim value. Whether any of it can be recovered from a contractor, landlord or anyone else depends on the contract terms and on who caused the delay — a legal question this tool does not answer.
- Does not estimate how long the delay will be.
- The lost contribution is the user's figure; rent, sales and production are not modelled.
- Excludes escalation of the remaining work, penalties under other contracts and tax effects.
Worked example
Produced by running this calculator with the inputs below.
Inputs
- Delay 30 calendar days
- Avoidable site overhead ₹5,000 a day
- Amount carrying interest ₹1,00,00,000 (₹1 crore)
- Annual interest rate 12%
- Day basis 365
- Lost contribution not entered
Working
- Site overhead = 30 × ₹5,000 = ₹1,50,000.
- Financing = ₹1,00,00,000 × 12% × 30 ÷ 365 = ₹98,630.14.
- Carrying cost = ₹1,50,000 + ₹98,630.14 = ₹2,48,630.14.
- Per day of delay = ₹5,000 + ₹1,00,00,000 × 12% ÷ 365 = ₹8,287.67.
Result. ₹2,48,630.14 (₹2.49 lakh) for a 30-day delay, excluding lost contribution.
Sensitivity — what moves the answer
- The length of the delay drives everything: at 12% the carrying cost is ₹1,24,315.07 for 15 days and ₹3,72,945.21 for 45 days.
- Two points on the rate moves the 30-day figure by about ₹16,438: ₹2,32,191.78 at 10% and ₹2,65,068.49 at 14%.
- On a 360-day basis the same interest is ₹1,00,000 — ₹1,369.86 more than on 365 days.
How engineers use the result
To put a daily figure on a delay when deciding whether to spend money to avoid it — extra shifts, a temporary supply, an earlier inspection booking — with overhead, interest and lost contribution kept visible as separate lines.
When a professional design must replace it
Before the figure goes into a negotiation, a claim or a board paper: finance should confirm the drawn balance, the rate and the day basis from the loan agreement, the site team which costs really stop when the job finishes, and a lawyer what, if anything, is recoverable.
Sources
- Simple interest: amount × annual rate × days ÷ day-count basis (actual/365 or actual/360) — standard day-count arithmetic; use the basis in your loan agreement
Questions people ask before using it
What do I need before calculating the cost of a delay?
The expected delay in calendar days; the site costs that continue only because the job runs longer (site staff, security, hired plant, temporary power and water, site office, insurance extension), taken from your site budget rather than the project total; the balance that carries interest through the delay with its annual rate and the day basis in the loan agreement; and, separately, any rent, margin or other contribution you lose by opening or producing later.
Which site conditions could change the delay cost?
Anything that changes the length of the delay or the daily cost: a further query on an approval or an inspection, hired equipment and temporary supplies that have to stay longer, more of the loan being drawn while you wait, a floating rate that resets, and a tenant or production start that moves with the delay. Some overhead stops when the site demobilises, so on a long wait the daily figure can fall — rerun it for each stage.
What should I send an engineer for a project-specific review?
The existing layout, the landlord's provisions (the power, water, fire and HVAC capacity available to you), the renovation scope and the programme showing which activity is late and why. An engineer can then check which MEP tasks drive the delay and whether any can be re-sequenced or run in parallel to shorten it.
Optional: ask an engineer to look at it
The result above is yours with no form. If you want an engineer to check it against your drawings, schedules or bills, send a request. Nothing is sent until you press the button.
Request saved
It reached our team with exactly what the preview showed. An engineer will use the number you gave if they need your drawings or data.
Prefer to talk? WhatsApp or the contact form.
Got your number — what next?
A calculator gives you a first figure. These take it further.