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Construction WIP calculator

Enter four numbers from one job — contract value, estimated total cost, cost to date, and billed to date — and get percent complete, earned revenue, over/under billing, and margin, computed the same cost-to-cost way your CPA and surety expect.

What the numbers mean

This calculator runs the standard cost-to-cost percentage-of-completion math used on construction WIP schedules: percent complete is cost to date divided by estimated total cost, earned revenue is percent complete times the revised contract value, and over/under billing compares what you have billed to what you have earned.

Overbilled (billings in excess of costs and estimated earnings) is a liability — you have collected for work not yet performed. A little is healthy for cash flow; a lot can hide a losing job. Underbilled (costs in excess of billings) is an asset — work performed but not yet invoiced, which usually means a pay application is overdue. For the full walkthrough, columns, and the mistakes that break a WIP, read how to build a WIP schedule.

Two cautions built into the math: percent complete is capped at 100% (cost overrunning the estimate means the estimate is wrong, not that the job is 110% done), and cost to date should be actual, source-document cost — including received-but-unbilled material — not an estimate.

This is one job, one month. A real WIP schedule runs this for every open job, every month, with cost to date pulled from job costing and billings pulled from your pay applications. That is what WIP schedule software does automatically.

Frequently asked questions

How is percent complete calculated on a WIP schedule?
Under the cost-to-cost method, percent complete equals cost incurred to date divided by the estimated total cost at completion. It is capped at 100%: if costs exceed the estimate, the estimate needs re-forecasting — the job is not more than finished.
What does it mean to be overbilled?
Overbilled (billings in excess of costs and estimated earnings) means you have billed more than the revenue you have earned through performance. It sits on the balance sheet as a liability. Modest overbilling keeps you cash-positive; large or growing overbillings can mask a job that is losing money.
What does it mean to be underbilled?
Underbilled (costs and estimated earnings in excess of billings) means you have performed work you have not yet invoiced — an asset. It usually signals billing is lagging the field, and the practical fix is getting a pay application out.
What numbers do I need to run this calculation?
Four per job: the revised contract value (original contract plus approved change orders), your current estimated total cost at completion, actual cost incurred to date from job costing, and total billed to date from your pay applications. The quality of the output depends almost entirely on keeping the cost estimate current.
Is this calculator free to use?
Yes — free, no signup, and nothing is stored; the math runs entirely in your browser. It is built by SitewideOps, whose platform computes the same cost-to-cost WIP across every open job automatically.

Keep exploring

Run this for every job, every month, automatically

SitewideOps computes cost-to-cost WIP across your whole project list from real job costs and pay applications, with month-end snapshots your surety can read.

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