What Is a Cost Estimates Document?

A Cost Estimates document is a quantitative assessment of the probable costs required to complete project work. In PMBOK 8, cost estimating is a process within the Project Cost Management performance domain — it produces estimates for each work package, which are then aggregated and time-phased to produce the Cost Baseline. Estimates include direct costs (labor, materials, equipment), indirect costs (overhead, administrative), and contingency reserves for known risks. They are living documents updated as more information becomes available, with estimate accuracy improving from rough order of magnitude (ROM) in initiation to definitive estimates during planning.

What's Inside This Cost Estimates Example

This Cost Estimates example covers Project Phoenix — a $72,250 website launch for MCG running March 17 to June 13, 2025. The spreadsheet contains:

• Labor Estimates tab: Hours and rates for each team member — Alex Morgan (PM, 240h at $85/h), the UX designer (180h at $75/h), the lead developer (320h at $90/h), the content specialist (160h at $65/h), the QA analyst (120h at $70/h), and the data migration specialist (80h at $75/h)
• Vendor Estimates tab: BrightFrame fixed-price design contract ($18,500), third-party plugin licenses ($2,400), hosting setup ($1,200)
• Other Direct Costs tab: Travel for stakeholder workshop ($800), software subscriptions during project ($650), printing and materials ($300)
• Contingency Reserve tab: $5,800 (8% of base estimate) calculated using Monte Carlo simulation on the three highest-risk work packages
• Estimate Basis tab: Estimation method (bottom-up), confidence range (±10%), assumptions underlying each estimate

How Alex Morgan Used This Cost Estimates Document

Alex Morgan built the cost estimates using a bottom-up approach: each work package in the WBS was estimated independently, then rolled up to phase and project totals. The estimation process involved the full six-person team — each specialist estimated their own work packages, which reduced optimism bias and increased ownership.

Three key estimation decisions shaped the project:

• Content migration estimate (ASM-007): The content specialist estimated 40 hours for migration based on the assumption of 90 legacy pages. When the content audit in Week 6 found 180 pages, the estimate doubled. Alex had flagged this as a high-uncertainty estimate in the Estimate Basis tab — that flag made it easier to invoke formal change control (CR-002) when the assumption proved wrong.
• BrightFrame fixed-price contract: Rather than estimating BrightFrame's labor hours, Alex negotiated a fixed-price contract at $18,500. This transferred cost risk to the vendor for the design phase, protecting the project budget from scope uncertainty in the creative process.
• Contingency reserve: The $5,800 reserve proved more than adequate. Of the seven issues (ISS-001 through ISS-007), only ISS-003 (server configuration failure) required contingency funds — approximately $1,800. The remaining $4,000 was returned to MCG at project close, contributing to the $10K under-budget result.

Download and Customize

This Cost Estimates example is available as a free download. Use it as a reference to build your own cost estimates, or start with the blank template and apply it to your project's work breakdown structure.

• Download the Cost Estimates Template — PMBOK 8 (blank, ready to use)
• Read the article: Cost Estimates in PMBOK 8 — Guide and Best Practices

Cost Estimates Example: Key Takeaways

The Project Phoenix Cost Estimates document is most instructive in what it reveals about estimate uncertainty. The content migration estimate was the single largest estimation error — off by 100% — yet it was also the estimate that had been explicitly flagged as high-uncertainty in the Estimate Basis tab. That flag did not prevent the error, but it ensured the team was mentally prepared for it and had a documented rationale for invoking change control when reality diverged from plan. The lesson: rigorous bottom-up estimating does not guarantee accuracy, but it does guarantee accountability. Every estimate that was wrong in Project Phoenix was traceable to a specific assumption — which meant the team could learn from it rather than simply blame it on "bad luck."

Want to go deeper? The PMBOK Guide 8th Edition is the definitive reference for modern project management. Get your copy and use it alongside these examples to build a solid, practical understanding of every performance domain.