Understanding COCOMO Schedule
How we calculate. Schedule months = 2.5 × person-months^0.38. See our methodology and accuracy policy .
Real-world scenario: Effort estimate of 100 person-months. Use those inputs in the COCOMO Schedule form to verify the on-page formula.
What is COCOMO Schedule?
Nominal schedule from Basic COCOMO. Compressing below this increases risk and often cost.
- PM = person-months of development effort
- Output is calendar months of development
- Staffing ≈ PM ÷ months as a rough average
The Formula
Worked Example
Common Use Cases
- Roadmaps: first-pass timelines
- Staffing: average headcount hints
- Risk talks: aggressive compression
Pro Tips
- Don’t force impossible compression
- Add integration/test buffers outside the model
- Use with effort estimate
| Scenario | When to use |
|---|---|
| Percent of a number | Finding a part of a whole (tax, tip, score) |
| Percent change | Comparing old vs new values |
Limitations: COCOMO Schedule results are educational software estimation aids—not bids, contracts, or performance scores. Calibrate models to your organization’s history.
Common mistakes
- Swapping part and whole: The denominator must be the full total, not a subset.
- Rounding too early: Carry extra decimal places through multi-step work before rounding the final percent.
- Mixing percent and decimal forms: Enter rates in the format the calculator labels expect.
The worked example for cocomo schedule was verified with the calculator form on this page—enter the same values to confirm the result.
When to use this calculator
- Use this page when your wording matches cocomo schedule and the form labels on screen.
- Use percent of a number for “what is X% of Y?” problems.
- Use number is what percent when you know part and whole and need the percent.
Still unsure about cocomo schedule? Start with the quick answer above, then open the linked calculator that matches your wording.
❓ Frequently Asked Questions
How do I use this cocomo schedule calculator?
For cocomo schedule, enter the values labeled on the form, then press Calculate. Compare the result to the worked example on this page.
What formula does this page use?
See the quick answer and formula box above for cocomo schedule—the same percentage calculator expression is applied to your inputs.
What if my result looks wrong?
When checking cocomo schedule, re-check part vs whole (or rate vs base), rounding, and whether percents were entered as 25 rather than 0.25 when the form expects percents.
Authoritative References
For estimation and quality models, consult:
- COCOMO — Constructive Cost Model overview
- IFPUG — function point standards
- SEI / Carnegie Mellon — software engineering practice