XS, S, M, L, XL, XXL… Not for your wardrobe, but for your agile tickets.
The principle
T-Shirt Sizing is a relative estimation method that classifies user stories using clothing sizes instead of numbers. It's deliberately approximate, and that's exactly the point.
The sizes typically used are: XS, S, M, L, XL, and even XXL for backlog monsters.
When to use it
This technique really shines during scoping or long-term planning phases, when you don't know the tickets well yet. It gives you a quick overview without getting lost in the details.
- Estimating an initial backlog (product discovery)
- Quarterly or annual roadmap
- Quick comparison between several features
- Teams not used to story points
Pros vs cons
Pros
- Accessible to everyone, even without agile experience
- Quick to set up
- Avoids endless debates over "is it a 5 or an 8?"
Cons
- Less precise for sprint planning
- Hard to convert into duration or velocity
- Subjective: one person's M is another's L
How to use it in practice
Start by identifying a reference story per size, a sort of benchmark. Then every new ticket is compared to these references. Is it bigger than an M? Smaller than an L? You have your answer.
Tip: use colour-coded post-its by size on a whiteboard. The visual really helps to position tickets relative to one another.
