Calculate when click on submit button

Hello there !

I would like to do this form : 2 numbers fields and 1 calculate field.

Users will enter some random numbers and the calculate field will return a result depending of the 2 others fields

The aim is to do something like this page (the calculators after the title “Simulateur de calories brûlées selon le poids, la distance parcourue et la vitesse” : https://marchons.com/marche-a-pied/bienfaits/marcher-pour-perdre-du-poids/ )

My problem is : I can’t succeed to make the “send button” like a “calculate button”. So when clicking, the numbers entered are deleted and I don’t have the result of the calcul

Is it possible to do something like this ?