Planning Poker vs T-Shirt Sizing: Which Method to Choose?
When it comes to estimating tasks in agile projects, two methods dominate: Planning Poker and T-Shirt Sizing. Both have their merits, but they’re ideal for different situations. Let’s compare.
What is T-Shirt Sizing?
T-Shirt Sizing uses clothing sizes (XS, S, M, L, XL, XXL) to categorize task complexity. It’s a quick and intuitive approach — everyone understands that XL is bigger than S.
What is Planning Poker?
Planning Poker uses numerical values from the Fibonacci sequence (0.5, 1, 2, 3, 5, 8, 13, 21) to estimate complexity. Each member votes independently, and votes are revealed at the same time.
Direct comparison
| Aspect | Planning Poker | T-Shirt Sizing |
|---|---|---|
| Precision | High — numerical values allow calculations | Low — broad categories |
| Speed | Moderate — discussion per item | Fast — intuitive categorization |
| Best for | Sprint planning, detailed tasks | Roadmap, backlog triage |
| Velocity calculation | Yes — sum of points | Difficult — how to sum “M + L”? |
| Discussion | Encourages deep discussion | Less discussion |
| Scale | Works for ~20 items per session | Works for 50+ items |
When to use Planning Poker
- Sprint Planning — when you need precise estimates for capacity planning
- Mature teams — that already have a calibrated reference scale
- Technical tasks — where implementation details matter
- Remote teams — with tools like Dev in Poker that facilitate online voting
When to use T-Shirt Sizing
- Backlog triage — to quickly categorize dozens of items
- Roadmap planning — when approximate estimates are sufficient
- New teams — that don’t yet have a reference for story points
- Non-technical stakeholders — who better understand “big” vs “small”
Hybrid approach
Many teams use both methods at different times:
- T-Shirt Sizing during backlog refinement for quick prioritization
- Planning Poker during sprint planning for detailed estimates
Items categorized as M in T-Shirt Sizing might receive 3-5 points in Planning Poker, while XL could become 13-21 points.
Conclusion
There’s no “better” method — there’s the method most suitable for the moment. Use T-Shirt Sizing for speed and overview, and Planning Poker for precision and detailed planning. What matters is that your team estimates consistently and collaboratively.