NEED AN EASY CALCULATOR

Hello. I want to do something quiet easy I guess but I don’t have enought knowledge.

I have this plugin (calorie calculator) that displays a result based on a formula.

But what I want is a calculator with some basic fileds like weight, height, gender… that displays just text that I customize. Not calculation just my own text, I mean, for example, someone with x weight and x height should take 40grams of my product in 200ml of water.

The page I need help with: [log in to see the link]