Calculated field with usage of global variable

Hello,

I have created a custom global variable because I want to use it inside a calculated form field and the same time to display this variable in various places on my website.

For example, my variable is [cgv?variable-name] and I want to create a form where the user will input a number in a text field e.g. 200 and the calculated field will display this: [cgv?variable-name]*200

I am using Elementor if it helps.

Could you let me know which form plugin supports this? I don’t mind if it is free or not.

Thank you