Retention Days Calculator

Calculator Inputs

Use business-day rules to mirror common contract timing. Add optional holidays as YYYY-MM-DD dates separated by commas.

Currency (3-letter code)

Example: USD, EUR, GBP

Invoice amount

Gross amount before retainage

Retainage percent (%)

Common ranges: 5–10%

Invoice date

Start date for retention days

Substantial completion date

When work is deemed substantially complete

Payment term days (Net)

Added to release dates

Release offset days after completion

Contract-specific waiting period

Defects / liens hold days

Often 30–90 days, varies by contract

Exclude weekends

Count business days only

If unchecked, calendar days are used

Holiday dates (optional)

Only applied when business-day counting is enabled

Partial release percent of retainage (optional)

Example: 50% at completion, rest later

Partial release days after completion

Add if contract allows early release

Example Data

Invoice Amount	Retainage %	Invoice Date	Completion Date	Hold Days	Net Days	Weekend Rule
USD 25,000.00	10%	2026-01-26	2026-04-11	30	14	Business days
USD 120,000.00	5%	2025-12-12	2026-03-07	60	30	Calendar days

These examples illustrate typical retainage settings. Always follow your contract, local requirements, and payment schedule.

Formula Used

Retainage Amount = Invoice Amount × (Retainage % ÷ 100)
Payable Now = Invoice Amount − Retainage Amount
Final Release Date = Completion Date + Release Offset Days + Hold Days + Net Days
Retention Days = Days between Invoice Date and Final Release Date
Business-day adjustment (optional): skip weekends and listed holidays while adding days

How to Use This Calculator

Enter your invoice amount, currency, and retainage percent.
Set the invoice date and the substantial completion date.
Add payment terms (Net days) and any contract release offsets.
Enter defects or lien hold days required before final release.
Enable business-day counting if your contract uses working days.
Optionally add holiday dates and a partial retainage release rule.
Press Calculate to view dates, retention days, and downloads.

Professional Notes

Why retention tracking matters

Retention is a common risk‑management tool in construction contracts. It protects owners against incomplete punch lists, lien exposure, and performance issues. For contractors and subcontractors, it directly affects working capital. Tracking retention days helps forecast when withheld amounts should convert into receivables and when follow‑ups are needed to avoid unnecessary delays.

Inputs that change release timing

Release timing is driven by contract milestones and administrative steps. Substantial completion dates, contractual offset periods, defects or lien hold windows, and net payment terms compound into a final release date. Partial releases may be allowed after completion or after specific inspections. Capturing these inputs consistently makes your forecast comparable across projects and pay applications.

Business days versus calendar days

Some agreements count calendar days, while others use business days. When business days apply, weekends are excluded and listed holidays may extend the schedule further. Using the correct day‑count method reduces disputes, especially when notice periods, inspection windows, or closeout deliverables are tied to working days rather than absolute dates.

Interpreting results for cash flow

The calculator reports retainage held, amount payable now, total retention days, and days remaining. Use the remaining‑days value to plan cash needs, equipment demobilization, and supplier payments. If the status shows due soon or past due, review closeout requirements, confirm acceptance documentation, and escalate with a clear, date‑based message to the paying party.

Documentation and audit readiness

Good recordkeeping speeds release. Maintain signed completion certificates, lien waivers, inspection reports, and punch‑list sign‑offs. Note any approved change orders that affect completion dates. Saving calculated outputs alongside supporting documents creates an audit trail. This helps finance teams reconcile retained amounts, reduces rework during reviews, and strengthens claims if timelines slip. For multi-tier projects, align your inputs with the prime contract and flow-down clauses. Confirm whether retainage reduces at a percent complete threshold or after commissioning. Always validate dates against the latest schedule update so the forecast reflects approved extensions and documented delays before sending any payment demand.

FAQs

What are retention days in this calculator?

Retention days are the number of days between your invoice date and the estimated final retainage release date, based on completion, holds, offsets, and payment terms.

Which completion date should I enter?

Use the contract-defined substantial completion date or the date accepted by the owner/engineer. If the project has phased turnover, use the completion date tied to the invoice scope and retainage clause.

How does excluding weekends change results?

When business days are used, weekend days are skipped while adding offsets, holds, and terms. This can push the release date later than a calendar-day method, especially for longer holds.

Can I model a partial retainage release?

Yes. Set a partial release percent and the number of days after completion when it becomes eligible. The calculator estimates a partial release date and keeps the final release date for the remaining balance.

What should I do if the status shows past due?

Recheck dates, holds, and closeout requirements. Confirm lien waivers, punch-list completion, and acceptance documentation. Then notify the payer with the calculated release date and supporting records to request immediate processing.

How should I enter holidays?

Enter holiday dates as YYYY-MM-DD values separated by commas. Holidays only affect results when business-day counting is enabled, because the calculator skips those dates while adding contract days.