Well, with all of one post under his belt, and the probability that he saw "Hops" and figured it made sense to ask here, I'm going to guess the OP is asking about brewing, not growing, and in that case, the answer could vary anywhere from a half ounce (BMC clones) to a dozen ounces (heavily dry-hopped IIPA).
Otoh, if my guess is wrong, make that anywhere from one to four plants or even more, depending on what you want to brew (and thus how many varieties are needed). You could likely do a pretty good SMaSH brew with the production from a single good bine (half pound dry weight)...
Cheers!