Pack calculator without php

I need a calculator for my website which converts metres into squared metres and then by the customer typing in the wood floor pack size calculates how many packs they need to buy.
i want it to work out how many packs only when then customer puts the pack size in themselves.
For an example of the kind of calculator i'm looking for please look at the web site calculator on www.ukflooringdirect.co.uk. however this calcalator selects the pack size for you when you pick your product i want mine to be a stand alone and bit more flexable.
It also needs to automatically add on 5% of the packs req'd to allow for cuts in the wood. So i just need someone to write the html code so i can copy and paste to my webite.
Also i tried a free mortgage calculator on the website to see if a calculator would work, i copied the html code and pasted into my web page it loaded ok but when you click calculate nothing happened.
so I called my website provider mr site and have found out that my website doesn't accept php or asp resolution it doesn't form action. That is what their people told me over the phone it means nothing to me but hopefully someone can tell me its ok and i can have the calculator i want as above. regards