The recipe for the original milk chocolate Hershey's bar has been around since 1900. Since then, Hershey's has expanded its chocolate bar line to include six flavors. The calories in each flavor vary slightly, but on average, a Hershey's chocolate bar will contain about 200 calories.

A serving size is one bar. Depending on the flavor, one bar is equal to 41 g or 43 g. The calories in each bar ranges from 180 to 220. The standard Milk Chocolate bar has 210 calories. The Special Dark and Extra Creamy bars contain the least number of calories at 180 each, and the Cookies 'n' Cream has the most calories, at 220.

Each Hershey's chocolate bar contains 6 g to 8 g of saturated fat, depending on the flavor. This is 30 to 40 percent of the recommended daily value established by the U.S. Department of Agriculture. A Hershey's chocolate bar also has 18 g to 24 g of sugar. The USDA does not provide daily sugar recommendations, although the agency does suggest minimizing the amount of added sugars in your diet. These include high-fructose corn syrup, maltose, corn syrup and dextrose.

A chocolate bar is not really meant to be a health food, although it can contain some good for you nutrients. The Hershey's Special Dark varieties contain 10 percent of the daily recommended value for iron. Dark chocolate also has antioxidant properties. The Cleveland Clinic suggests choosing dark chocolate over milk chocolate.