Task Size Estimation List

Here's a common way to define sizes for task estimation, often used in agile methodologies:

Size Code	Size Name	Man-days ▲ ▼	Description
XS	Extra Small	1	Very simple tasks, can be completed very quickly, minimal risk.
S	Small	2	Simple tasks, quick to complete, minimal risk.
M	Medium	3	More complex, may involve some dependencies, moderate risk.
L	Large	5	Significantly complex, multiple dependencies, higher risk, requires more coordination.
XL	Extra Large	8	Very complex, major dependencies, high risk, may involve multiple team members.
XXL	Extra Extra Large	13	Extremely complex, significant dependencies, very high risk, potentially requires breaking down into smaller tasks.

To convert from Size Code to Man-days, you can use a Google Sheets formula like: Copy where A2 contains the Size Code.

Here is the list of Size Codes: XS, S, M, L, XL, XXLCopy

Why these numbers?

They use a modified Fibonacci sequence (1, 2, 3, 5, 8, 13...) which provides a good spread to differentiate between sizes.
It's not a linear progression, reflecting the increasing uncertainty and effort as tasks grow larger.

Man-days are estimates: They represent the effort required, not necessarily the exact duration. Factors like availability, interruptions, and dependencies can affect the actual time to complete a task.
Team agreement is key: The most important thing is that the team agrees on the relative size of each category.
Relative vs. Absolute: These sizes are relative to each other, not absolute measures of time. An "L" task should be roughly twice the size of an "M" task, but the actual time may vary.
Consider your team: A specific team might find that their "M" is closer to 2.5 days. The values can be adjusted to what best reflects the team's capacity and past performance.