Abstract: The invention calculates the precise amount of insulin needed by someone (the user) who is diabetic and/or insulin/insulin-pump user, in order to keep the user's blood sugar concentration in the previously set target, and provides a practical method to make the necessary changes (weekly, monthly, every other month, etc) in the personal carbohydrate ratio profile, and more specifically the invention, calculates the user's carbohydrate ratio at any given time and allows the user to determine the amount of insulin (Bolus) to be injected.