What is cost to complete, and why does it matter?

Cost to complete is your estimate of what you will still spend to finish a job. Add it to what you have spent so far and you get the forecast final cost.

Forecast final cost = cost to date + estimated cost to complete.

Why it matters

It is the earliest warning that a job is losing margin, while there is still time to change something. Doing it by cost code shows where the problem is, labor, material, or subcontractors, instead of one number for the whole job.

Do it well

Estimate what is actually left to do, not just what is left in the budget. A worked example is in How to build a cost-to-complete forecast that you can trust.