Calling 2x and 3x potsize bets

in theory, when an opponent bets 2x the pot on the river we must be ahead at least 40% of the time for our call to be profitable. ex. pot size x opponent bets 2x pot size now 3x to call 2x so 3:2pot odds in other words we need to win 2out of 5 times.

As !luck and daviddem said, having an actual hand here would help a ton. But, fwiw, in most situations, I think that if we are even considering calling a 2x-3x pot sized bet on the turn or river, then our hand better be strong enough to go all in with, and we should just be shoving...not calling.