Cost-to-Complete (CTC) vs. Estimate-at-Completion (EAC): How to Forecast Profit Accurately
In construction, profitability isn’t determined when a contract is signed. It’s determined by how accurately project teams can predict costs throughout the life of the project and make adjustments before small issues become expensive surprises.
Two of the most important forecasting metrics in construction financial management are Cost-to-Complete (CTC) and Estimate-at-Completion (EAC). While they are closely related, they serve different purposes and provide unique insights into project health and profitability.
Understanding the difference between CTC and EAC can help contractors improve cash flow, identify risk earlier and make more informed business decisions.
What Is Cost-to-Complete (CTC)?
Cost-to-Complete (CTC) represents the amount of money required to finish all remaining work on a project.
In simple terms, it answers the question:
“How much more will we need to spend to complete this project?”
CTC includes projected labor costs, materials, subcontractor expenses, equipment costs and any other anticipated expenses that have not yet been incurred.
Cost-to-Complete Formula
CTC = Estimated Remaining Project Costs
For example:
- Original project estimate: $1,000,000
- Costs incurred to date: $600,000
- Remaining projected costs: $350,000
In this example:
CTC = $350,000
A well-maintained CTC forecast allows project managers to proactively address budget overruns before they impact project profitability.
What Is Estimate-at-Completion (EAC)?
Estimate-at-Completion (EAC) is the projected total cost of the project once all work is completed.
Rather than focusing only on future spending, EAC combines actual costs already incurred with the estimated costs still remaining.
It answers the question:
“What will this project cost us when everything is finished?”
Estimate-at-Completion Formula
EAC = Actual Costs to Date + Cost-to-Complete
Using the previous example:
- Actual costs incurred: $600,000
- Cost-to-Complete: $350,000
The calculation becomes:
EAC = $950,000
If the contract value is $1,100,000, the projected profit would be:
Projected Profit = Contract Value – EAC
Projected Profit = $1,100,000 – $950,000 = $150,000
This allows contractors to forecast margins long before project closeout.
The Difference Between CTC and EAC
While the two metrics work together, they provide different perspectives on project performance.
| Metric | Focus | Key Question |
|---|---|---|
| Cost-to-Complete (CTC) | Remaining costs | How much more do we need to spend? |
| Estimate-at-Completion (EAC) | Total projected project cost | What will the entire project cost when complete? |
Think of CTC as looking forward while EAC looks at the entire financial picture.
Why Accurate Forecasting Matters
Many contractors rely solely on original estimates or percentage-of-completion calculations to understand profitability. Unfortunately, construction projects rarely go exactly according to plan.
Scope changes, labor shortages, material price increases, weather delays and productivity issues can quickly impact margins.
Regularly updating CTC and EAC forecasts helps contractors:
- Identify potential cost overruns early
- Improve cash flow forecasting
- Make informed staffing decisions
- Reduce surprises during project closeout
- Improve overall financial visibility
- Protect projected profit margins
The earlier a problem is identified, the more options teams have to correct course.
Common Forecasting Mistakes
Even organizations that track CTC and EAC can run into problems if forecasting practices are inconsistent.
Some common mistakes include:
Waiting Too Long to Update Forecasts
Monthly reviews may not be enough on fast-moving projects. Weekly updates often provide better visibility into emerging risks.
Ignoring Field Input
Project managers and superintendents often have the most accurate understanding of labor productivity, subcontractor performance and upcoming challenges. Financial forecasts should incorporate field knowledge rather than relying solely on accounting data.
Assuming Original Estimates Are Still Valid
Material prices, labor availability and project conditions change throughout construction. Forecasts should reflect current realities rather than historical assumptions.
Treating Forecasting as a Finance Exercise
Accurate forecasting requires collaboration between operations, accounting and leadership teams. The best forecasts combine financial data with project intelligence.
How Construction Software Improves CTC and EAC Accuracy
Manual spreadsheets make it difficult to maintain accurate forecasts across multiple projects. Modern construction management software provides real-time visibility into budgets, commitments, change orders and actual costs.
When project teams can access current financial information in one place, they can update forecasts faster and identify risks earlier.
Integrated financial forecasting tools also reduce duplicate data entry and improve consistency across accounting and operations teams.
Final Thoughts
Cost-to-Complete (CTC) and Estimate-at-Completion (EAC) are two of the most important metrics for understanding project profitability.
CTC helps contractors understand what remains to be spent, while EAC provides a complete picture of projected project costs and expected profit.
Used together, these forecasts allow construction leaders to make proactive decisions, protect margins and deliver more predictable financial outcomes.
The most profitable contractors aren’t simply the ones that win the most work. They’re the ones that know exactly where every project stands financially before the job is complete.
