Calculations Through a Form (Contact Form 7?)

I have a form on my website that captures height, weight and basic information about a person. I can capture the basic info using contact form 7, but after the form is submitted, I need the height and weight to have some basic multiplication applied to it and then have the result of that multiplication shown on the following page.

Normally I can do this through PHP, however I’m not sure how to manipulate post data through page when it comes to passing it through a WordPress page (page template).

Any suggestions on how to accomplish this? PS – the data doesn’t need to be capture in a database, just need to be shown on the screen after the user fills out the form.

Thanks