Depends on how many worms you are feeding. These bags are 8 ounces and make a bowl of food a little larger than the size of a softball. I have never mixed up a whole 8 ounce bag at one time, because I never have more than 200 Silks or 50 Goliaths at one time (this food works for Goliaths as well). The food if refrigerated keeps 4 ever, so buy enough you pay less shipping.