The number of calories burned from doing 100 jumping jacks can vary depending on factors such as age, weight, and intensity level. On average, a person who weighs around 150 pounds can burn approximately 10-12 calories for every 10 jumping jacks. Therefore, doing 100 jumping jacks may burn around 100-120 calories. However, it's important to keep in mind that this is just an estimate and individual results may vary.