Ok, good enough question. Let me give you an easy rule to remember: You can always put a larger magazine into a smaller gun. You can NEVER put a smaller magazine into a larger gun.
I will put these in order for you. Starting with the model on the left, work your way to the right. The first model listed is the largest followed by descending capacity in order.
Regarding 9mm pistols: The first 3 models are all the same size 17/17L/34 followed by 19/26
Regarding 40 pistols: The first 3 models are all the same size 22/24/35 followed by 23/27
Regarding the 357 Sig pistols 31/32/33
Regarding the 45 GAP pistols 37/38/39
Regarding the 10mm pistols 20/29
Regarding the 45 ACP pistols 21/30
*The G36 stands alone. It will not fit anything else.