T-Shirt Sizing

T-Shirt sizing is a very popular technique to provide relative abstract sizing for backlog items.

T-Shirt Sizes

Just like the name suggests, common T-Shirt sizes include:

• small (S)
• medium (M)
• large (L)

For additional granularity of sizes the below may also be used:

• extra small (XS)
• extra large (XL)
• extra extra large (XXL)

Relative Sizing

An approach that is common in Agile Estimation is to use relative sizing to size items relative to each other. One common technique for T-Shirt Sizing is to use a 2 series where an S is equivalent of one unit of work or effort required to complete the item, and a M is equivalent to 2 x S and so on:

• XS = 0.5 x S
• S = 1
• M = 2 x S
• L = 2 x M
• XL = 2 x L
• XXL = 2 x XL

This series then provides an exponential scale to work with and can be used in conjunction with Affinity Estimation for example.

See Also

• Affinity Estimation
• Agile Estimation
• Story Mapping