Free construction working-capital tool
Construction Retainage Cash Flow Calculator
Measure how much cash is trapped between owner retainage and downstream retainage, how long it stays trapped, and what that does to working capital and project profit.
Simple retainage model
Retainage GapMeasure the owner-to-subcontractor retainage mismatch
Project economics
Retainage structure
Retainage release waterfall
Retainage-gap logicOwner retainage is cash withheld from project billings. Downstream retainage is cash the contractor can temporarily retain from subcontractor/vendor costs. The difference is the contractor-funded retainage gap. The model assumes billings and downstream retainage-eligible costs accrue evenly for Simple-mode financing estimates, then applies the entered substantial-completion releases and final release delay.
Retainage Release Waterfall
Simple project modelWhere the trapped cash changes at closeout
Release-delay sensitivity
Cost of waiting longer for final retainage
| Final release delay | Gap held after substantial completion | Retainage carrying cost | Total working-capital drag | Adjusted project margin |
|---|
Advanced monthly cash model
Cash Trap TimelineBuild the 12-period Retainage Cash Trap Timeline
Project & liquidity assumptions
12-period project schedule
PeriodBillings / earned revenueProject cost paidDownstream cost subject to retainageOwner retainageDownstream retainage
Timeline logicOrdinary collections are shifted into later monthly buckets using the entered collection lag rounded up to whole months. Project costs are paid in the period entered, net of downstream retainage withheld. Owner and downstream retainage balances accumulate monthly, then release according to the substantial-completion and final-release assumptions. The timeline extends beyond Month 12 when payment lag or final retainage release requires it.
12-Period Cash Trap Timeline
Timeline extends through final releaseCollections, cost payments, retainage and liquidity by period
| Period | Ordinary collections | Owner retainage release | Cost cash paid | Downstream retainage release | Owner retainage balance | Downstream retainage balance | Net retainage gap | Net cash flow | Project cash balance |
|---|
Retention mismatch
Which project periods create the most retainage pressure?
| Period | Billings | Owner retainage added | Downstream retainage added | Incremental retainage gap | Cumulative gap before releases |
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Owner vs. downstream retainage stress matrix
All other schedule assumptions held constantPeak cash gap under different retainage-rate combinations
Final-release delay sensitivity
Working-capital drag as closeout stretches
| Final release delay | Peak retainage gap | Retainage carrying cost | Total working-capital drag | Adjusted gross margin |
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Scope
Use the actual contract and applicable law for retainage requirements
Retainage percentages, release timing, reduction rules, payment deadlines and subcontractor obligations vary by contract, project type and jurisdiction. This calculator uses only the assumptions you enter. It does not determine whether retainage is permitted, whether it must be reduced or released by a particular date, or whether owner and subcontractor retainage terms may legally differ.