Finance

What is cost to complete in construction?

Cost to complete is the estimate of how much more a job will cost, from today to final completion, to finish the remaining scope.

An office manager and contractor review invoices with a calculator and laptop in a construction office.
Review invoices, committed costs, and cash timing together before making project decisions. AI-generated illustration.

Cost to complete (often written CTC) is the dollar amount a contractor still expects to spend to finish a job. It is not the budget minus what has been spent. It is a fresh, honest forecast of the labor, material, subcontract, equipment, and general conditions cost left on the remaining work. Add it to cost to date and you get the estimate at completion, the number that tells you what the job will really earn.

This is the single most important input on a WIP report. Get it wrong and percent complete, revenue, overbilling, and profit are all wrong with it.

How cost to complete works on a real job

The project manager walks the job, looks at what is installed, and asks each line of the budget one question: what will it take to finish this? Open subcontracts and purchase orders count as committed cost still to be invoiced. Self-performed labor is forecast from remaining quantities and the crew's actual production rate, not the rate in the bid.

Say a concrete contractor has a $640,000 foundation package with a $560,000 cost budget. Cost to date is $310,000. The budget says $250,000 is left. But the PM knows the remaining footings are deeper than drawn, the pump truck is billing more per pour than planned, and the rebar sub has $42,000 left on its subcontract.

Example: cost to complete by cost type
Cost typeBudget remainingForecast cost to complete
Self-performed labor$118,000$141,000
Concrete and materials$64,000$69,000
Rebar subcontract$42,000$42,000
Equipment and pumping$16,000$24,000
Job overhead$10,000$12,000
Total$250,000$288,000

The forecast is $288,000, not $250,000. Estimate at completion becomes $598,000 against a $640,000 contract, so expected gross profit drops from $80,000 to $42,000. Better to learn that in month three than at closeout.

Common mistakes with cost to complete

  1. Using budget minus cost to date as the forecast. That assumes everything from here goes exactly to plan, which is rarely true on a job already over on some lines.
  2. Leaving out committed costs that have not been invoiced yet, so the forecast looks low until the sub's next bill lands.
  3. Ignoring pending change orders. Approved changes raise both contract and cost. Unapproved extra work still costs money now.
  4. Letting the office fill it in alone. The superintendent knows what is really left in the building.
  5. Updating it once a quarter. Monthly is the minimum on most jobs, and weekly reviews catch margin fade faster.

Related terms

Cost to complete sits next to balance to finish (which is usually about the contract value left to bill), budget variance, and the percentage of completion method, which uses cost to date divided by estimate at completion to recognize revenue. Smart Business Automator's job costing and WIP views pull committed and actual cost onto each line so the PM only has to forecast what is truly left.

Frequently asked questions

Is cost to complete the same as remaining budget?

No. Remaining budget is the original or revised budget minus cost to date. Cost to complete is a new forecast of what the remaining work will actually cost, which can be higher or lower.

Who should prepare the cost to complete?

Usually the project manager, with input from the superintendent and foremen on remaining quantities and production. Accounting supplies cost to date and open commitments.

How does cost to complete affect overbilling?

Under percentage of completion, a higher cost to complete lowers percent complete, which lowers earned revenue. If billings stay the same, the job swings toward overbilling.

How often should cost to complete be updated?

At least monthly, before the WIP schedule is closed. Many contractors review it weekly on large or troubled jobs.

Written and edited by

Maurice Francois writes and edits construction operations guides for Smart Business Automator. More from Maurice on the Scaling Legends podcast.

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