What is the T-shirt sizing estimation exercise?

T-shirt sizing is an estimation technique, using t-shirt sizes ranging from XS to XL to estimate upcoming work items. This estimation technique shows the relative effort to deliver items, without getting into granular (and often incorrect) time estimates.

Estimating work items in t-shirt sizes gives is a quick way of giving a measure of effort to assist roadmap and prioritization efforts. The t-shirt sizing process also starts the scoping conversations to understand the requirements of the upcoming items.

How to run the T-shirt sizing exercise

1. Import your items to the board from a CSV file, or add them manually (psst – JIRA integration coming soon).
2. It helps to provide sizes of previous work items, or get the team to size items of work they have completed recently.
3. Take the first item, and ask the team to select a t-shirt size from their hand of cards, and place it face down on the table.
4. Reveal all estimates at once, review them, and discuss any variances.
5. Once the size of the item is agreed, move it to the ‘Items Estimated’ section.
6. Repeat with the next items, until all items are estimated or time is up.