How good odds do you need to risk your tournament life. The odds probably differ depending on how much chips you have in comparison to the blind.

In the last 2 tournaments I've played I was eliminated early because I was all-in being 89% favourite in one (top-set against runner-runner straight, guy had AA) and over 90% favorite in the other (flopped boat against higher boat on river). I think in thoose cases it was correct to go all-in since I was such a favorite when the money went in but where does the line go? Being 70%, 60%, coinflip? We are talking about even money situations here.

Is it possible to set up any guidlines, I realize teory says as long as you have pot-odds it's ev+ but the tournament life has to be calculated into the formula or am I wrong?