How to Produce a Cost-to-Complete You Can Defend

The Number Everything Else Depends On

Your percentage complete comes from costs incurred divided by total estimated costs. Total estimated costs is costs incurred plus cost to complete. So cost to complete drives your percentage complete, which drives your revenue recognition, which drives your reported profit.

Get it wrong and everything downstream is wrong — your WIP schedule, your income statement, the numbers your surety is underwriting against.

And yet in a great many contracting businesses, cost to complete is calculated as budget minus actual. Which quietly assumes the original budget was perfect and nothing has changed since. On a job that is running badly, that assumption hides the problem right up until the end.

Why Budget Minus Actual Fails

Picture a job budgeted at 1,000 labor hours for a scope. You are halfway through the physical work and 700 hours are gone.

Budget minus actual says 300 hours remain. But the work is only half done and it has taken 700 hours so far. The honest estimate is another 700, possibly more if the difficult part is still ahead. Budget minus actual reports a small problem. Reality is a 40% overrun.

The method works only when nothing has gone wrong. It fails exactly when you need it most.

Build It From the Work Remaining

A defensible cost to complete is built bottom-up, by cost code, from the work that is physically left:

• Labor — remaining quantity times a realistic unit rate. Use the rate you are actually achieving on this job, not the estimated rate, unless you can point to a specific reason the remaining work will run differently.
• Materials — open purchase orders plus an estimate for what is not yet ordered, at current prices rather than bid prices.
• Subcontracts — remaining contract value plus any change orders in negotiation that you expect to approve.
• Equipment — remaining duration times rate, including standby where the schedule implies it.
• General conditions — remaining months times the monthly burn, which is often understated when a job is running late.

That last one catches people. If a job extends by two months, general conditions extend too, and that cost is real whether or not anyone budgeted for it.

Who Should Own the Number

The project manager, with the accountant challenging it. Not accounting alone — the office does not know what is physically left. Not the PM alone either, because the PM has an incentive, conscious or otherwise, to report that things are fine.

The productive version of this is a short monthly conversation per job: the PM walks through remaining scope by code, the accountant asks where the numbers come from, and both sign off. Fifteen minutes a job, and it surfaces most problems a month or two before they would otherwise appear.

The Questions That Make It Defensible

When reviewing a cost-to-complete, these five questions find most of what is wrong:

• What unit rate are you assuming for remaining labor, and how does it compare to what we have achieved so far?
• What is not yet procured, and are those numbers bid prices or current prices?
• Are there change orders in the remaining scope that are not yet approved?
• If the schedule slips another month, what does that add?
• What is the single thing most likely to go wrong from here, and is it in this number?

A PM who can answer those has thought about it. One who cannot is giving you budget minus actual with extra steps.

When You Are Genuinely Uncertain

Sometimes you do not know — a claim is unresolved, a design is incomplete, a sub is in trouble. The answer is not to pick a comfortable number. It is to estimate a range, use the conservative end for reporting, and document why.

Under US GAAP, if a loss on the contract is probable and can be estimated, the full loss is recognised immediately, not spread across the remaining job. That rule exists precisely because optimistic cost-to-complete estimates were being used to defer bad news. A surety that discovers you deferred a known loss will remember it far longer than the loss itself.

What Good Practice Looks Like

Monthly, by cost code, built from remaining work, owned by the PM, challenged by accounting, documented enough that you could explain it to a lender a year later. Anything less and your WIP schedule is a well-formatted opinion.

Our Job Cost & WIP Diagnostic reviews exactly this — how your cost-to-complete is built and whether the WIP resting on it would survive scrutiny.