Retainage Calculator for Construction Contracts

Retainage is withheld from every draw, and the balance adds up fast. Know exactly how much is being held before you submit each application.

Enter your contract value and retainage rate to calculate the amount withheld, the amount paid each draw, and what releases at substantial completion.

What this calculation means

Retainage is a percentage of each progress payment that the owner or GC holds back as security until the project reaches substantial completion or final completion. A typical retainage rate is 10 percent, meaning 10 cents of every dollar you bill is withheld until closeout. On a large commercial project, the withheld balance compounds significantly before it is released. Many specialty contractors underestimate how much working capital is tied up in retainage across their active projects.

Why this number matters

Understanding your withheld retainage balance at every draw is essential for cash flow management. The calculator above shows the balance per project; the real number you care about is the total across your portfolio. Retainage is also a lien risk: if the GC fails to pay and you have a retainage balance, your lien rights protect that balance. Know the number so you can protect it.

Common calculation mistakes

How to use this calculation

1. Confirm the retainage rate in your subcontract before the first draw

   The rate is specified in the subcontract. Common rates are 5%, 10%, or a stepped schedule. Know the rate before you submit.
2. Track the cumulative withheld balance each period

   After each draw, calculate the total withheld balance to date. This is your current retainage exposure.
3. Confirm the retainage release trigger

   Substantial completion? Final completion? A specific calendar date? Know the trigger and track toward it.
4. Submit the retainage release request on time

   When the trigger is reached, submit the release request with the required documentation: punch list sign-off, final lien waiver, as-built documentation, and any other contract-required attachments.

Where Scaftra automates this

Scaftra tracks retainage withheld and released as part of the Pay Application workflow. Each draw shows the gross amount billed, the retainage withheld, and the net amount due. The running balance is visible throughout the project lifecycle, so there is no end-of-project calculation required.

Related features

• Pay Application retainage tracking: Retainage is calculated and tracked per draw, per period, with the cumulative balance carried forward automatically.
• Schedule of Values: Retainage is calculated per SOV line, matching how the GC processes the draw.
• Lien waiver management: Conditional waivers are tied to the draw amount, so the waiver amounts are correct.

What getting this right delivers

• Know your retainage exposure at every draw: no end-of-project surprises.
• Correct retainage math every period: no manual calculation errors.
• On-time release request: know the trigger, submit on the trigger date.
• Retainage protected: know the balance that is exposed if payment is delayed.

Who uses this calculator

• Trade contractors on commercial projects with retainage.Any subcontractor billing under a retainage contract needs to understand their withheld balance and release schedule.
• Controllers managing cash flow across multiple projects.The aggregate retainage balance across active projects is a working capital exposure. The calculator shows the per-project piece.
• Project managers preparing the final pay application.The final draw includes the retainage balance. Knowing the exact amount helps you prepare the application correctly.

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