Of the many things consider before entering a pot, stack sizes are one of the most important. The obvious one is your own stack and how many chips you have in absolute terms, and what the relationship is between your stack and the current blind level.

Assuming you have a comfortable stack and are under no pressure from the blinds and antes, you need then to consider your stack in relation to those of the people still to act behind you in the hand.

Common thinking suggests a stack size hierarchy where you should avoid confrontations with the big stacks as they are the only ones at the table who can bust you.