Understanding COCOMO Basic Effort
How we calculate. Person-months = 2.4 × KLOC^1.05 (organic Basic COCOMO). The form uses the same arithmetic as the worked examples on this page. See our methodology and accuracy policy.
Real-world scenario: A project estimated at 50 KLOC (organic). Use those inputs in the COCOMO Basic Effort form to verify the on-page formula.
What is COCOMO Basic Effort?
Classic Boehm COCOMO Basic organic model for relatively small, familiar projects. Intermediate/Detailed COCOMO add cost drivers not included here.
- Organic coefficients: a=2.4, b=1.05
- KLOC = thousands of delivered source lines
- Planning aid only—calibrate to your org
The Formula
Worked Example
Common Use Cases
- Early bids: ballpark staffing
- Portfolio compare: size vs effort
- Teaching: estimation models
Pro Tips
- Don’t use for embedded/semidetached without other modes
- Calibrate KLOC definition (comments? generated?)
- Pair with schedule model
Limitations: COCOMO Basic Effort results are educational software estimation aids—not bids, contracts, or performance scores. Calibrate models to your organization’s history.
FAQ
Organic vs semidetached vs embedded?
This tool uses organic Basic coefficients. Other modes use different a/b values.
What if KLOC is 0?
Effort is 0—enter a positive size estimate.
Authoritative References
For estimation and quality models, consult:
- COCOMO — Constructive Cost Model overview
- IFPUG — function point standards
- SEI / Carnegie Mellon — software engineering practice