Form Factory’s reference scale for estimating user stories. Uses a Fibonacci-like sequence that combines time, complexity, and uncertainty into a single number. Supports the INVEST criteria (Estimable, Small) from user-story-guide.

The Matrix

PointsTimeComplexityUncertainty
1A few minutesLittleNone
2A few hoursLittleNone
3A dayLowLow
5A few daysMediumModerate
8A weekMediumModerate
13Two weeksHighHigh
21A monthVery HighVery High

Rules

  • 21 points = must split. A story estimated at 21 is too large — break it into smaller stories (see user-story-guide on epics).
  • The practical working range for sprint-ready stories is 1–13.
  • Story points measure relative effort, not just calendar time — complexity and uncertainty matter as much as duration.