🎴 Decks & scales
Planning Poker Cards & the Fibonacci Sequence
Why agile teams estimate with 1, 2, 3, 5, 8, 13 instead of 1–10, what each card means, and how to pick the right deck for your team — with free online cards.
Why Fibonacci and not 1 to 10?
The Fibonacci sequence — 1, 2, 3, 5, 8, 13, 21 — grows so each number is roughly the sum of the two before it. Those widening gaps are the whole point: the larger a piece of work, the less precisely anyone can size it. Forcing a choice between an 8 and a 13 (rather than agonising over a 9 versus a 10) keeps estimation fast and honest about uncertainty.
What each card roughly means
Teams calibrate their own scale, but a common rule of thumb: 1 is a trivial change, 2–3 is a small well-understood task, 5 is a solid day or two of work, 8 is a large story you might still complete in a sprint, and 13+ is a signal to split the story before committing. The exact mapping matters less than the team agreeing on it.
The ½ and 0 cards
Some decks add ½ for near-trivial work and 0 for items already done. Use them sparingly — they invite false precision.
The ? and ☕ cards
A “?” means “I need more information to estimate.” A coffee card signals “let's take a break.” Both keep sessions human.
Fibonacci vs T-shirt sizing
T-shirt sizes (XS, S, M, L, XL) suit teams that find raw numbers stressful or are estimating at a coarse, roadmap level. They convert cleanly to points later if needed. Fibonacci suits sprint-level estimation where you want comparable numbers to sum into a velocity. Many teams use T-shirts for quarterly planning and Fibonacci inside the sprint.
Frequently asked questions
▸Why does planning poker skip 4, 6, 7 and 9?
The Fibonacci gaps widen on purpose. Removing close-together numbers stops teams from over-debating tiny differences that don't change the plan.
▸What is modified Fibonacci?
A rounded variant — 0, ½, 1, 2, 3, 5, 8, 13, 20, 40, 100 — that keeps larger numbers memorable for bigger, fuzzier work.
▸Can I make my own deck?
Yes. Planning Poker Hero lets you build a custom card set, so you can use any scale your team prefers.
▸Are physical and online cards different?
Only in delivery. The values and rules are identical; online cards just let distributed teams reveal simultaneously in a shared room.
Related guides
Deal the cards — free
Pick Fibonacci, T-shirts, or a custom deck and start estimating with your team.