Hi Reddy,
Simple concept: Each 4K block is 1 node. lets say you have 1TB volume, the number of inodes you can have is: (1024 * 1024 *1024)/4= 268435456 inodes. The best practice is use upto 75 to 85% of nodes of a volume. If you further need the inodes, you better increase the size of the volume and increase the inodes after the threshold is reached (85% inodes consumption).
First 1024 is GB and second 1024 is mb and third 1024 is KB - This is just a note.
I hope this is very clear to you.
thank you,
AK G