Work & Business

Contractor Retainage Cash-Flow Calculator

Retainage reduces cash received now even though the contractor may already have paid labour, materials, and subcontractors. This calculator separates the current progress payment from the amount held, then estimates simple carrying cost during the expected release delay. Contract rights, lien rules, tax treatment, and enforceability depend on jurisdiction and agreement.

Planning estimate only. Check measurements and real-world constraints before buying materials or making a commitment.

Last Updated: July 9, 2026

Calculate your scenario

Change any input. Results update immediately.

Approved work billedProgress billing before retainage.$Retainage withheldContract holdback percentage.%Other current deductionsBackcharges or agreed deductions.$Expected release delayTime from progress payment to retained cash receipt.daysAnnual cash carrying rateBorrowing or opportunity-cost estimate.%Expected retainage recoveredShare expected to be collected eventually.%

Your results

Current progress cash

$210,000.00

Approved billing less retainage and entered deductions.

Retainage held

$24,000.00

Gross amount withheld under the scenario.

Estimated carrying cost

$869.92

Simple cost on expected recovered retainage during delay.

How the calculation works

The calculator applies this relationship to the inputs above. Keep every measurement in the unit shown.

retainage carrying cost = amount held × annual carrying rate × delay days ÷ 365

Approved work billed240000 $

Retainage withheld10 %

Other current deductions6000 $

Expected release delay150 days

Annual cash carrying rate9 %

Expected retainage recovered98 %

Worked example

Use this example to check the calculator by hand before relying on a result.

Find retainage

This cash is withheld from the progress billing.

$240,000 × 10% = $24,000

Find current cash

Costs may have been paid before this receipt.

$240,000 − $24,000 − $6,000 = $210,000

Estimate carrying cost

The model assumes 98% of retainage is eventually collected.

$23,520 × 9% × 150 ÷ 365 = $870

Assumptions behind the result

• Billed work is approved.
• Retainage applies before other deductions.
• Carrying cost uses simple interest.
• Recovery percentage is an estimate.
• Legal and tax rules are reviewed separately.

Mistakes that change the answer

• Treating billed revenue as available cash.
• Ignoring the time value of holdback.
• Assuming every retained dollar will be released on schedule.

Questions about contractor retainage cash-flow calculator

Is retainage the same as profit?

No. It is part of contract payment withheld temporarily; profitability depends on all revenue, costs, claims, and collection outcomes.

Why estimate recovery below 100%?

Punch-list deductions, disputes, insolvency, documentation, and collection friction can reduce or delay final receipt.

Can retainage rules limit the percentage or delay?

Yes. Requirements vary by jurisdiction and project type, so review current legal and contract terms.

What to calculate next

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Calculator methods and editorial structure reviewed July 11, 2026. Results are estimates; verify regulated rates, eligibility rules, and professional decisions with the cited primary source.