How to Calculate Training Max for 5 Progression?

I’ve used 531 for a good portion of my training over the past 5 years in a fairly simple format, but I’ve always used 90% of my gym max for my TM. Typically iit was a top single ,double or triple and I applied the described formula.
My second exercise/movement was either done as SST ( my favorite) BBB ( which was too much) or 5sPRO. I would just make rough guess on what a top 5RM would be when done after the main movement and reduce by about 10%-15%.
I am looking for some help on how to determine my TM when using 5 progression for the main exercise ,squat,bench,DL, press.
I own the original 531, 2nd edition , 531 for PL and beyond. The last book is the only book that describes 5s progression ,but in my reading not in this manner.
Thank you in advance, it seems there are many very knowledgeable people who will share advice and experience on this forum.

Find a weight that you can complete five strong reps with.

That is your TM.


In general, 85% is the safest TM when doing additional volume work (BBS, BBB, FSL, SSL). However, you can use a lower TM for supplemental work due to the fatigue.

Thank you.
I am working on trying to follow the concept of the training max and apply it to my individual goals.
I am used to thinking of training in a linear progression. Move forward , hit a wall , back up then move forward again. Learning to apply the TM to a larger program to reach my goals is a little more challenging. But that’s good.
Thank you for the help