Finding potential activity.

[SmallCapCoins]

What is the best way to figure out my macimum potential activity that includes prior weeks?

[TryNinja]

Get your Bitcointalk UID - (you can do that by clicking on your name at any of your posts and looking at the end of the url) - and use the Bitcointalk Price Estimator[1] to fetch your account's information. It will show your Potential Activity and weeks left for your next rank.

[1] https://www.bctalkaccountpricer.info/

[botany]

What is the best way to figure out my macimum potential activity that includes prior weeks?

The site given by TryNinja is the best way to find out potential activity.
In your particular case (or anybody with posts > activity), the potential activity = activity.