One 3-ounce box of Jell-O will make about 16 single-ounce Jell-O shots. Three ounces is the typical standard size box for most kinds of gelatin.
Jell-O shots can be made with any flavor of gelatin. To make a Jell-O shot, start by mixing 1/2 cup water with 1/4 cup vodka or another distilled spirit, then chill the mixture. Boil 1 cup of water, and mix it with the gelatin in a bowl until the gelatin dissolves completely. Add in the chilled liquor and water as well as food coloring, if desired. Pour the Jell-O into shot glasses, and refrigerate the glasses until the liquid sets. It should take at least 2 hours, but it's recommended to refrigerated the shots overnight.