When buying watermelon, we often encounter the problem of determining its ripeness. A ripe watermelon is considered when it is no longer filled with liquid, but rather begins to give up this liquid, i.e. vyat. Based on this, an application was developed that calculates on the basis of the mass and the circumference of the fruit its ripeness. With this application you can determine the ripeness of watermelon. Also this application will be useful when consulting customers.