COCOMO II Cost Calculator
Cost a COCOMO II effort estimate at your own person-month cost.
What this calculator does
Effort from the published post-architecture equation with constants A = 2.94 and B = 0.91, then costed at the user's own person-month cost. The nominal scale-factor sum and nominal multiplier product are shown as published defaults and may be changed.
Inputs and what they mean
- Currency
- — Amounts are shown in the currency you pick. No exchange rate is applied..
- 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. 18.97 is the published nominal sum..
- Product of the effort multipliers
- — Multiply your rated effort multipliers together; 1 means nominal..
- Loaded cost of one person-month
- — number value.
- Tools, licences and other non-labour cost (optional)
- — Optional component. Leave at 0 to exclude it from the result..
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
PM = 2.94 × KSLOC^(0.91 + 0.01 × ΣSF) × ΠEM; Cost = PM × Loaded cost per person-month + Non-labour cost
Worked example
100 KSLOC at your own person-month cost
Published COCOMO II constants with your ratings; the money figure is yours.
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
Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.
Reference: University of Southern California, Center for Systems and Software Engineering — COCOMO II model definition manual
Last reviewed:
Common questions
Formula, source and verification
The published post-architecture effort equation, costed at the loaded person-month cost the organisation enters.
The question it answers: What will this development cost, using the published estimation model?
The formula
PM = 2.94 × KSLOC^(0.91 + 0.01 × ΣSF) × ΠEM; Cost = PM × Loaded cost per person-month + Non-labour cost
- Size — Size
- (KSLOC). Thousands of source lines of code.
- ΣSF — Sum of the five scale factors
- (points). The organisation's own ratings; 18.97 is the published nominal sum.
- ΠEM — Product of the effort multipliers
- (factor). The organisation's own rated multipliers; 1 is nominal.
- c — Loaded cost of one person-month
- (currency). Employer cost of one person-month, entered by the organisation.
- N — Non-labour cost
- (currency). Optional tools, licences and other non-labour cost.
Units: KSLOC; person-months; currency.
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
Effort from the published post-architecture equation with constants A = 2.94 and B = 0.91, then costed at the user's own person-month cost. The nominal scale-factor sum and nominal multiplier product are shown as published defaults and may be changed.
Assumptions built into the result
- Industry: Size, scale factors and effort multipliers are rated by the user under the published rating scales.
Figures this calculator will never guess for you
- No industry delivery rate, productivity figure, defect rate or cost per line is inserted.
- No optional component is filled in on the user's behalf.
- No person-month cost is supplied by the calculator.
Limitations
- COCOMO II is a calibrated estimation model, not an exact prediction; its published accuracy is a range, not a point.
- Estimates are only as good as the size, scale factors and effort multipliers entered.
Source and version
- Standard or reference
- COCOMO II post-architecture model — University of Southern California, Center for Systems and Software Engineering (COCOMO II Model Definition Manual — post-architecture effort PM = A × Size^E × ΠEM with A = 2.94 and E = B + 0.01 × ΣSF (B = 0.91), and schedule TDEV = C × PM^(D + 0.2 × (E − B)) × SCED%/100 with C = 3.67 and D = 0.28.)
- Published source
- University of Southern California, Center for Systems and Software Engineering — COCOMO II.2000
- Formula version
- Version 1
- Verification
- Reviewed against the cited source on
- How much weight the source carries
- Academic
- Applies to
- Currency
- Amounts stay in the currency you choose; no exchange rate is applied.
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