965 to 966 Hershey Kisses can be accommodated in a jar of one gallon, if they are stuffed perfectly close to each other and air tight. This is because, one Hershey kiss chocolate weighs 4.56 grams, and therefore, a gallon of Hershey Kisses be equal to 4404.8 grams approximately. That means, the number of Hershey kisses that can be stuffed is 965 to 966.