Conventional wisdom states that you need a better hand to call a raise than to raise yourself. It’s called the “Gap Theory”. The theory is that to profitably call the raise, your hand must play well against the range of hands which your opponent may hold. And many of the hands you’d raise with don’t perform well against a standard raising range.
Additionally, calling creates an assumption of risk from players yet to act, further weakening your holding. So,all else being equal, it’s generally true that you must have a better hand to call a raise with than you would raise with yourself.
For example, a tight player raises upfront, indicating a strong range and you hold KJ in the cutoff, a fold is in order. But had it passed to you, you would have an easy raise.
But your holding isn’t the only edge you can hold over an opponent. Your ability to play your hand, the strength of your opponent’s range, the texture of players yet to act and position are also very important factors. You must incorporate all those elements into your decision.
So, while it often does take a stronger hand to call a raise than raise with yourself, consider all elements of the situation. Is there a way to increase your equity? Are there features of your opponent’s play that you can exploit? Are you considering all the risks?
Don’t just play by set guidelines; make sure you think through all the possibilities.
And make your best decision.