Hello I am looking for an extensive set of calculators on my site for users and am wondering where I should look? Are website calculators done in HTML? Are there any designers on these forums who contract w/ Elance? Are there companies who sell (advertisement free) calculators?
Calculators are one of the easiest things to code, even for beginners. The language you should look for is Javascript. There are several different types of calculators, so I can't link you to one. Google 'javascript calculator script' or something of the sort. gl
As PoohBear88 said, calculators are done with Javascript or PHP. You can easily find these scripts using Google. However, have you considered Google Analytics? Create an account there, get scripts for your pages and then you will have many statistics of your website. It's free.