So I haven't experimented a lot with 72p SIMMs, but I did see that a rule of thumb is that if the individual memory chips have 4 sets of 6 legs, each chip will have 2 megabytes (so 8 or 9 of these chips make 16MB and 16 or 18 (usually half on each side) would mean a 32MB SIMM).
If the individual chips have 4 sets of 5 legs each, then the memory size is 4 times less (so half a megabyte for each chip).
There's usually 3 different sizes of chips used on 72p SIMMs (excluding the more older and obscure ones) which are most commonly used for pentium class motherboards. The ones with 4x6 legs on each chip, the ones with 4x5 legs on each chip, and the very long chips with one very long row of legs on ech side of the chips.
These chips are also 2MB each and are usually found with 2 of the very large memory chips on each side. 2 of these chips on a side with both sides filled up will give 8MB total for the whole SIMM. I've seen some which have 4 of the very large chips on each side (the SIMM will be a bit taller to make room for a second row of 2 chips on the PCB) and these SIMMs will be 16MB.
I have a very few 72p SIMMs which have very flat and more square-ish looking chips which look more similar to what one could find on the first gen SDRAMs (the 16MB or 32MB PC-66 ones used for 430VX machines for instance) and these can be much higher capacity.
I didn't include everything of relevance and see this as a rule of thumb only and not a golden standard. This however made it easy for me to sort large amounts of modules quickly and recognizing modules quickly if I just wanted a set of SIMMs for a quick test in a hurry.