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Retainage Calculator: Pay Application Math, Step by Step

By Oussama Chicha, EditorUpdated Checked against primary sources · not yet reviewed by a licensed professionalFormula shown below · see the math
Quick answer

Current payment due = (work completed + stored materials − retainage) − previous certificates already paid. A $250,000 contract with $125,000 of work and $10,000 of stored materials at 10% retainage, less $90,000 already certified, pays $31,500 on this application.

Your pay application

Results update as you type
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$
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Retainage
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%
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Total already paid on prior applications, before this one.
Project
Project type
Shows your state's retainage rule below, when we have it verified.
Current payment due · liveSheet 01
Current payment due
$31,500
Retainage on work
$12,500
Retainage on stored
$1,000
Total retainage
$13,500
Total earned
$135,000
Earned less retainage
$121,500
Balance to finish
$128,500
% complete
54.0%
The math for your numbers
Retain/work    = $125,000.00 × 10% = $12,500.00
Retain/stored  = $10,000.00 × 10% = $1,000.00
Total retain.  = $12,500.00 + $1,000.00 = $13,500.00
Total earned   = $125,000.00 + $10,000.00 = $135,000.00
Earned − ret.  = $135,000.00 − $13,500.00 = $121,500.00
Payment due    = $121,500.00 − $90,000.00 = $31,500.00
Balance        = $250,000.00 − $135,000.00 + $13,500.00 = $128,500.00
% complete     = $135,000.00 ÷ $250,000.00 = 54.0%

Sources and defaults

No external data: this calculator is pure arithmetic, with the formulas shown above.

What retainage is

Retainage is the slice of every pay application the owner holds back until the job, or a defined phase of it, is done. If a contract sets 10% retainage and you bill $125,000 of work this month, $12,500 stays unpaid until later, even though the work is complete and inspected. It exists to give the owner leverage to get punch-list items finished and liens cleared before the last dollar moves.

The rate, what it applies to, and when it comes back are all contract terms first. Many contracts set retainage somewhere in the 5–10% range and release it at substantial or final completion, but the number that controls your job is the one written in your contract, not a percentage from a blog post. Where a state has passed a retainage statute, it can cap the rate, force a step-down, or set a legal release deadline regardless of what the contract says. This calculator's guidance panel shows that rule once we have verified and published it for your state.

The pay-app math, line by line

This is the same arithmetic behind AIA G702 (Application and Certificate for Payment) and its G703 continuation sheet, two of the most common forms this math appears on. Both are published by the American Institute of Architects. The calculation is identical whatever form your contract uses:

Retainage on work = work completed × retainage % on work
Retainage on stored materials = stored materials × retainage % on stored materials
Total earned = work completed + stored materials
Earned less retainage = total earned − total retainage
Current payment due = earned less retainage − previous certificates already paid

Worked example: $125,000 of work and $10,000 of stored materials, both at 10% retainage, is $135,000 earned and $13,500 held back, leaving $121,500 earned less retainage. Subtract $90,000 already certified on prior applications and this application pays $31,500.

Step-down retainage

Some contracts reduce the retainage rate once the job passes a completion threshold (say, from 10% down to 5% once the contract is 50% complete), so the owner's leverage shrinks as the risk does. The math splits the work into two slices and applies each rate to its own slice:

Retainage on work = (work up to the threshold × rate before) + (work past the threshold × rate after)

For a $250,000 contract with a 50%-complete threshold, 10% before and 5% after: $175,000 of completed work splits into $125,000 below the threshold and $50,000 above it, for retainage of $12,500 + $2,500 = $15,000. That is less than the $17,500 a flat 10% on the whole $175,000 would hold back.

Over-billing

If work completed plus stored materials adds up to more than the contract sum, the calculator flags it. That is not automatically fraud. It usually means change orders that raised the contract sum have not been entered into this application yet, but it is worth checking before the application goes out. The same section also flags the opposite problem: when previous certificates already paid add up to more than the current amount earned less retainage, the application shows a credit rather than a payment, which is also worth a second look before you send it.

How to use this calculator

  1. Enter the contract sum and the work completed and materials stored on site as of this application.
  2. Set the retainage rates. Work and stored materials are often, but not always, the same percentage.
  3. Turn on step-down if your contract reduces the rate after a completion threshold, and set the threshold and reduced rate.
  4. Enter previous certificates: everything already paid on this contract before this application.
  5. Pick your project type and state to see your state's retainage rule in the panel, once we have verified and published it.
  6. Copy the page link to save or share the result. Nothing you type leaves your browser.

FAQ

Is retainage the same on private and public jobs?

Usually not. States that regulate retainage typically set separate rules for private and public (government) contracts, sometimes with a different cap, a different release trigger, or no statute at all on one side. This calculator asks for your project type so the guidance panel can show the rule for the contract you actually have, once we have a verified record for your state.

When do I get my retainage back?

Whatever your contract says: usually at substantial completion, final completion, or a fixed number of days after one of those, sometimes tied to a punch list being cleared. Some states set a legal release deadline on top of the contract, which is what this calculator's state panel shows when we have verified it. Read the retainage clause in your contract first. It controls unless a statute overrides it.

Does retainage apply to change orders too?

Usually, yes. Most contracts retain the same percentage on change-order work as on the original scope, unless the change order itself says otherwise. Add change-order amounts into work completed to date once they are approved, the same way the original scope is billed.

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