Bananas' yellow skin means you don't have to wash your fruit before you eat it, which is ideal whether you're grabbing a healthy snack for the drive home or are enjoying this nutrient-rich fruit after working out. The calories in a banana range from fewer than 75 to more than 130, depending on the length of the fruit.
Length Determines Caloric Value
The size of your banana dictates its caloric value. A banana of 6 inches or fewer has about 72 calories, according to the U.S. Department of Agriculture National Nutrient Database. A 6.5-inch banana has 90 calories, while a 7.5-inch banana has 105 calories. A banana that measures 8.5 inches has 121 calories, while a fruit longer than 9 inches has 135 calories. One cup of banana slices has 134 calories.