Fibonacci Sequence
Fibonacci is the planning poker industry standard — used in over 90% of sessions. The sequence (0, 1, 2, 3, 5, 8, 13, 21…) is not arbitrary: the widening gap between numbers is intentional. A 13 is not just "a little more" than an 8 — it carries significantly more uncertainty. That growing gap reflects a real truth about software estimation: the bigger a piece of work, the harder it is to predict precisely. Choosing Fibonacci means you are not pretending that large stories can be estimated with the same confidence as small ones. The high end of the deck (34, 55, 89) also serves as a signal: when a story estimates that high, the right conversation is not "what's the number?" but "how do we split this?"
Cards: 0, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89.
How to use Fibonacci Sequence in planning poker
Begin refinement with the Product Owner reading the story aloud and fielding questions — no estimates yet. When the team is ready, each person privately selects a card. The facilitator counts down and everyone reveals simultaneously. Simultaneous reveal prevents anchoring: nobody sees a "5" and adjusts their "8" to match before the count. When the spread is wide — say a 3 and a 13 — ask the outliers to explain first. The high vote often surfaces a technical risk; the low vote often reveals a simpler interpretation that nobody had considered. One re-vote usually converges. If the team genuinely cannot agree after two rounds, either split the story or accept the higher estimate and flag the uncertainty in your tracker.
Example tasks and point mappings
Concrete mappings teams commonly land on: 1 (fix a typo or swap a config value), 2 (CSS layout adjustment, copy change), 3 (add a form field with validation), 5 (new REST endpoint with tests), 8 (new screen with authentication and state management), 13 (refactor an existing module without changing its API), 21 (add a third-party integration end-to-end), 34+ (split the story — it is too large to commit to confidently).
When to consider a different deck
Fibonacci's mathematical concept can confuse teams that are brand new to agile. If your team regularly spends more time debating "is this a 5 or an 8?" than discussing the actual work, consider Simple Numbers as a starting point. For epic-level roadmap planning with non-engineering stakeholders, T-Shirt Sizes are a better fit.
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