Free template · Excel
Free Software Estimation Template (Excel)
Estimate a software project task by task, as a range instead of a single guess. The sheet does the PERT math, adds visible buffers for real risks, and gives you two numbers to share: one at about 84% confidence and a safer one at about 95%.
Download (.xlsx)
Works in Excel and Google Sheets · No sign-up · Updated
What's inside
- Estimate: Deliverables and tasks with optimistic, most likely, and pessimistic days. Calculates the PERT estimate (O + 4M + P) ÷ 6 and a rough standard deviation for every task, plus actual days and variance as work finishes. Includes example rows for the work people forget: code review, QA, deployment, documentation, and meetings.
- Summary: At the top of the Estimate sheet: expected effort, an estimate to share at about 84% confidence, a safer one at about 95%, and rough calendar weeks for your team size.
- Risks & buffers: One visible buffer per real risk, with a plan such as a spike. Mark a buffer as released when the risk doesn't happen, and it drops out of the total.
- How to use: Step-by-step instructions and notes on what the numbers mean.
Preview
Example rows from the Estimate sheet (days):
| Deliverable | Task | Optimistic | Most likely | Pessimistic | PERT |
|---|---|---|---|---|---|
| Checkout | Cart summary screen | 1 | 2 | 4 | 2.2 |
| Checkout | Payment provider integration | 3 | 5 | 15 | 6.3 |
| Work people forget | QA testing and bug fixing | 2 | 3 | 6 | 3.3 |
How to use it
- Break the work into deliverables and small tasks. Split any task over a few days.
- Keep the rows for code review, QA, deployment, documentation, and meetings.
- Ask the person who will build each task for optimistic, most likely, and pessimistic days.
- List real unknowns in Risks & buffers, each with its own visible buffer.
- Share the range with its assumptions, then fill in actual days as work finishes.
To use it in Google Sheets, open Google Sheets, choose File, then Import, and upload the file. The dropdowns and formulas carry over.
The full guide behind this template: Software Development Estimation: My 7 Steps.