Attention, this article refers to the version of Google Analytics Universal that is no longer continued by Google. The latest version of Google Analytics is Google Analytics 4.
To determine the optimal size of the pool, we use the number of visitors per month as a guide. #
I can see the unique visitors/users on the start page. Select the last complete month as the time period. If there are fluctuations, compare the last 3 months to calculate an average value.
Under Users you will now find the Unique Visitors:
Using this number, you can now determine the pool size to obtain the best tracking results:
ARTICLE: How do I find the right pool size for my website?