Retainage Calculator

This calculator tracks progress payments and retainage on a construction contract. Work Completed equals Contract Value times Progress Complete, and Total Retained is the smaller of two figures: the straightforward Retainage Rate applied to work completed, or a compounded cap built from Retainage Cap (expressed as a fraction of contract value) multiplied again by the Retainage Rate. Because Retainage Rate cancels out of that comparison, the cap binds as soon as Progress Complete passes Retainage Cap itself -- at the default 50% cap, that's just past the halfway point of the project, not "far along": at the default 45% complete, 10% retainage, and 50% cap, Progress Complete (45%) is still under Retainage Cap (50%), so Total Retained is $90,000 (10% of the $900,000 completed) and the cap doesn't bind yet; push Progress Complete to 90% (past the 50% cap) and Total Retained is capped at $100,000 instead of the $180,000 that a straight 10% would otherwise withhold. Contract Value and Progress Complete have an identical proportional effect on every dollar output ONLY while the cap doesn't bind -- once it does, Progress Complete's effect on Total Retained disappears entirely (the capped figure no longer reads Progress Complete at all), while Contract Value keeps moving Total Retained proportionally even then, because the cap itself is expressed as a percentage of Contract Value and scales right along with it.

Retainage Rate moves Retainage Held and Total Retained directly but has a much smaller effect on Net Amount Paid, since the paid amount is the much larger work-completed figure minus the much smaller retainage. Retainage Held and Total Retained always show the identical number, as do Net Amount Paid and Net Payment -- this calculator computes a single cumulative snapshot as of today rather than tracking separate periods, so there's no period-over-period distinction for "held so far" versus "retained overall," or "paid this draw" versus "paid net of retainage," to show separately; a period-by-period retainage ledger would need those pairs to diverge. This models a common AIA-style retainage schedule but doesn't account for contract-specific retainage-reduction clauses or stored materials not yet installed.