T-Shirt Sizing
A lightweight relative estimation technique where backlog items are sized using T-shirt sizes (XS through XL) instead of story points or hours. It removes the false precision of numeric estimation, encourages discussion about relative effort, and works especially well for early-stage roadmap planning when details are unclear.
How to run it
- 1
Establish anchor items first: find one item that is clearly 'M' (medium) and one that is 'S'. Use these as reference points.
- 2
Present backlog items one at a time.
- 3
Each team member silently picks a T-shirt size and reveals simultaneously (to avoid anchoring bias).
- 4
If consensus: move on. If disagreement: the outliers explain their reasoning briefly, then re-estimate.
- 5
Record the agreed size against each item.
- 6
After the session, optionally map sizes to story points: XS=1, S=2, M=5, L=8, XL=13.
Tips
Use T-Shirt Sizing for epics and features. Use Planning Poker for sprint-level stories.
Disagreement is signal — two people with very different sizes have different mental models. That's worth a 2-minute discussion.
Don't let the session become about hours. It's about relative complexity.
Keep a 'parking lot' for items that generate repeated disagreement — they need splitting.
Variations
Bucket System: place items in buckets (XS, S, M, L, XL) rather than estimating one by one — much faster for large backlogs (50+ items). Animal Sizing: some teams use animals (mouse=XS, elephant=XL) to further remove numeric anchoring.
Where it fits
Related methods
Plan your next workshop with AI
Workshop Weaver helps you combine methods like T-Shirt Sizing into a complete, timed agenda in minutes.
Try it freeMethod descriptions on Workshop Weaver are original content written by our team, based on established facilitation practices. This method was inspired by work from Workshop Weaver.