There is no one correct answer to this question because potatoes vary in size and length. In foodservice, the size ranges for no. 1 potatoes are determined by the USDA. Each carton of fifty pounds contains an average county of potatoes. For example, a 50-count potato would average around 1 pound each. However, the length could be long or short, so the circumference will vary. The most common size of potato shipped from Idaho is 80 or 90 count, which is smaller than a 50-count potato. Here’s a size chart with the actual potato sizes shown in ounces:

Idaho Potato Commission Size Guide