How many flutter kicks burn 1 calorie?

Doing flutter kicks for one hour burns approximately 5 Calories per kilogram per hour, so if you're a male weighing 70 kilograms and do one hour of flutter kicks, you can burn:

(5 x 70 x 1)kcal/h = 350 Calories per hour.

To find out however many flutter kicks burn one calorie, divide the number you do by 350, and that will be your answer. This will vary depending on how intense/quickly you do the workout.