COCOMO II Effort and Schedule Calculator
Estimate development effort, schedule and average team size for a software project of a known size.
In short
Estimate development effort, schedule and average team size for a software project of a known size.
Formula: E = A × Size^(B + 0.01 × ΣSF) × EM; TDEV = C × E^(D + 0.2 × (B_exponent − B)); Team = E ÷ TDEV, with A = 2.94, B = 0.91, C = 3.67, D = 0.28
Estimated effort
465.3 person-months
- Scale exponent
- 1.0997
- Estimated schedule
- 25.9 months
- Average team size
- 18 people
- Effort per KSLOC
- 4.65 person-months
Estimate produced by a recognised estimation model, for informational purposes only. Formula version 1; last reviewed 2026-09-15.
What this calculator does
The published post-architecture equations: effort in person-months from size in thousands of source lines, then schedule from effort. The published constants are applied to the size, scale-factor sum and effort-multiplier product entered by the estimator. The calculator does not rate the project for you and inserts no calibration of its own.
Use it to turn Size, Sum of the five scale factors, Product of the effort multipliers into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this professional & industry calculation.
Inputs and what they mean
- Size
- — Thousands of source lines of code..
- Sum of the five scale factors
- — Your own ratings for precedentedness, flexibility, risk resolution, team cohesion and process maturity..
- Product of the effort multipliers
- — Multiply your rated effort multipliers together; 1 means nominal..
How to use it
- Enter your own figures — the calculator never fills in a rate, price or benchmark for you.
- Press Calculate to see the result.
- Read the formula, variables, assumptions and source below the result before you rely on it.
Formula
E = A × Size^(B + 0.01 × ΣSF) × EM; TDEV = C × E^(D + 0.2 × (B_exponent − B)); Team = E ÷ TDEV, with A = 2.94, B = 0.91, C = 3.67, D = 0.28.
Inputs used: Size, Sum of the five scale factors, Product of the effort multipliers.
Edge handling: Size is required.; Size must be greater than zero.; Size must be no more than 100000.; Sum of the five scale factors is required.; Sum of the five scale factors cannot be negative..
Worked example
100 KSLOC project at nominal ratings
- Start with Size: 100, Sum of the five scale factors: 18.97, Product of the effort multipliers: 1.
- Apply the method: E = A × Size^(B + 0.01 × ΣSF) × EM; TDEV = C × E^(D + 0.2 × (B_exponent − B)); Team = E ÷ TDEV, with A = 2.94, B = 0.91, C = 3.67, D = 0.28.
- Published COCOMO II post-architecture constants applied to your ratings.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Inputs outside the supported range are rejected rather than forced into a result.
- The result depends on the values you enter for this cocomo ii effort and schedule calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Reference: SEI / USC — COCOMO II model definition manual
Last reviewed:
Common questions
Where does this formula come from?
COCOMO II model definition manual, post-architecture effort and schedule equations with published constants. See the source link on this page.
What kind of calculation is this?
The published post-architecture equations: effort in person-months from size in thousands of source lines, then schedule from effort. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
What are its limits?
An estimation model, not a measurement. Accuracy depends entirely on the size estimate and ratings supplied.
How do I use the COCOMO II Effort and Schedule Calculator?
Enter the required values for Size, Sum of the five scale factors, Product of the effort multipliers. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the COCOMO II Effort and Schedule Calculator use?
E = A × Size^(B + 0.01 × ΣSF) × EM; TDEV = C × E^(D + 0.2 × (B_exponent − B)); Team = E ÷ TDEV, with A = 2.94, B = 0.91, C = 3.67, D = 0.28 The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
Can the COCOMO II Effort and Schedule Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Formula, source and verification
The published post-architecture equations: effort in person-months from size in thousands of source lines, then schedule from effort.
The question it answers: How many person-months and how many calendar months is this project likely to take?
The formula
E = A × Size^(B + 0.01 × ΣSF) × EM; TDEV = C × E^(D + 0.2 × (B_exponent − B)); Team = E ÷ TDEV, with A = 2.94, B = 0.91, C = 3.67, D = 0.28
- Size — Size
- (KSLOC). Thousands of source lines of code.
- ΣSF — Sum of scale factors
- (points). Sum of the five scale-factor ratings entered by the estimator.
- EM — Effort multiplier product
- (factor). Product of the effort multipliers the estimator has assessed.
- E — Effort
- (person-months). Estimated development effort.
- TDEV — Schedule
- (months). Estimated calendar duration.
Units: KSLOC in; person-months and calendar months out.
What kind of calculation this is
Estimation model. This is a published estimation model. It produces an estimate, not a measured fact, and its accuracy depends on how well your situation matches the model.
Method
The published constants are applied to the size, scale-factor sum and effort-multiplier product entered by the estimator. The calculator does not rate the project for you and inserts no calibration of its own.
Assumptions built into the result
- Operational: Size is expressed in thousands of source lines of code.
- Industry: Scale factors and effort multipliers have been rated by the estimator.
Figures this calculator will never guess for you
- No default scale factors, effort multipliers or productivity rates are supplied.
- No cost is produced without an entered rate.
Limitations
- An estimation model, not a measurement. Accuracy depends entirely on the size estimate and ratings supplied.
Source and version
- Standard or reference
- COCOMO II.2000 post-architecture model — USC CSSE (COCOMO II model definition manual, post-architecture effort and schedule equations with published constants.)
- Published source
- SEI / USC — COCOMO II.2000
- Formula version
- Version 1
- Verification
- Reviewed against the cited source on
- How much weight the source carries
- Academic
- Applies to
- Currency
- The result is a ratio or index, so it does not depend on currency.
Cite this page
Free Calculator. (2026, September 15). COCOMO II Effort and Schedule Calculator. https://freecalculator.tech/tools/cocomo-ii-estimate-calculator
"COCOMO II Effort and Schedule Calculator." Free Calculator, 15 Sept. 2026, https://freecalculator.tech/tools/cocomo-ii-estimate-calculator.
COCOMO II Effort and Schedule Calculator — Free Calculator, https://freecalculator.tech/tools/cocomo-ii-estimate-calculator
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