COCOMO Software Effort Estimator (Basic COCOMO)

What this tool does

Barry Boehm's Basic COCOMO (1981) estimates effort from size alone: Effort = a × KLOC^b, with a and b depending on the kind of project, followed by Time = 2.5 × Effort^d. Because b is above 1, effort grows faster than size, a sign that large projects lose productivity to communication, and because d is only about a third, doubling the team does not halve the time. 50 KLOC in an organic project comes to about 146 person-months over some 17 months. It was calibrated on 63 projects of the 1970s; use it for order-of-magnitude planning, not as a promise.

Formula

Effort = a × KLOC^b [person-months] · Time = 2.5 × Effort^d [months] · Team = Effort ÷ Time (Basic COCOMO: organic 2.4/1.05/0.38, semi-detached 3.0/1.12/0.35, embedded 3.6/1.20/0.32)

Variables

Worked example

Limitations

• The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
• The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.