How many planets are in the whole galaxy?
That is currently unknown. However, based on the planets found so far it seems there are at least as many planets as stars. Current estimates suggest 100 billion to 400 billion planets in our galaxy.
It is not generally known how many planets are in each galaxy; it isn't even known how many planets are in our own galaxy, and will probably never be known exactly, due to its enormous size. However, according to latest observations, it seems likely that every star has several planets, at least on average.