Estimation Rule of Thumb

An time estimation rule of thumb for software development in startups. (Somewhat tongue-in-cheek.)

The rule

  • Make a good estimate of the work (in any time unit).
  • Multiply that number by itself in months plus one.
  • What you get is a reasonable estimate for release date (in the original time unit).


Some examples:

  • Work estimated to one week will take one week.
  • Work estimated to two weeks you can expect to be ready in close to a month.
  • Work expected to take two months weeks will take about six months.
  • Anything estimated to half a year or more won’t be finished. The scope will be changed too much before the project is finished.

While not perfectly scientific, it is actually more or less empirically derived from my own company’s history.