# COCOMO II Schedule Calculator

> Estimate calendar time with the published COCOMO II schedule equation.

Page: https://freecalculator.tech/tools/cocomo-ii-schedule-calculator
Last reviewed: 2026-09-16

## Formula

TDEV = 3.67 × PM^(0.28 + 0.2 × (E − 0.91)) × SCED% ÷ 100, where PM is the nominal-schedule effort and E = 0.91 + 0.01 × ΣSF

- TDEV = 3.67 × PM^(0.28 + 0.2 × (E − 0.91)) × SCED% ÷ 100, where PM is the nominal-schedule effort and E = 0.91 + 0.01 × ΣSF.
- Inputs used: Size, Sum of the five scale factors, Product of the effort multipliers, Required schedule compression.
- 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..

## Inputs

- Size
- Sum of the five scale factors
- Product of the effort multipliers
- Required schedule compression

## Worked example: 100 KSLOC on the nominal schedule

The published schedule equation, with compression left at 100%.
1. Start with Size: 100, Sum of the five scale factors: 18.97, Product of the effort multipliers: 1, Required schedule compression: 100.
2. Apply the method: TDEV = 3.67 × PM^(0.28 + 0.2 × (E − 0.91)) × SCED% ÷ 100, where PM is the nominal-schedule effort and E = 0.91 + 0.01 × ΣSF.
3. The published schedule equation, with compression left at 100%.

## Common questions

### Where does this formula come from?

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. See the source link on this page.

### What kind of calculation is this?

The published schedule equation applied to the post-architecture effort estimate. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.

### What are its limits?

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. Compression outside the published 75%–160% range is refused rather than extrapolated.

### How do I use the COCOMO II Schedule Calculator?

Enter the required values for Size, Sum of the five scale factors, Product of the effort multipliers, Required schedule compression. 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 Schedule Calculator use?

TDEV = 3.67 × PM^(0.28 + 0.2 × (E − 0.91)) × SCED% ÷ 100, where PM is the nominal-schedule effort and E = 0.91 + 0.01 × ΣSF 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 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.

## 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 schedule calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.

## Sources

- University of Southern California, Center for Systems and Software Engineering — https://csse.usc.edu/tools/cocomo/

## Cite this page

- APA: Free Calculator. (2026, September 16). COCOMO II Schedule Calculator. https://freecalculator.tech/tools/cocomo-ii-schedule-calculator
- MLA: "COCOMO II Schedule Calculator." Free Calculator, 16 Sept. 2026, https://freecalculator.tech/tools/cocomo-ii-schedule-calculator.
- Link: COCOMO II Schedule Calculator — Free Calculator, https://freecalculator.tech/tools/cocomo-ii-schedule-calculator