I'm a programmer have done a lot of Blizzard calculators. I did a CTC and a Haste Breakpoint calculator for WOW and have been working on a DPS/ EHP Calc for D3 that will do both at once and give some nice information breakdowns.
This is the link to my Calculator. What is special about this Calculator? It will allow you to type in your name and tag number and load all your characters info. No more inputting each item manually. Once you have uploaded your character you will be presented with multiple breakdowns of your stats including DPS and EHP, and per item breakdowns. Also you will be presented with an input sheet that allows you to input new items. You can insert multiple new items at once and just make sure to click the New checkbox. Once you have done this hit calculate and you can compare and contrast how this new item will affect your overall stats!
Why are my stats different than other sites?
This can be multiple reasons. My calculator automatically loads your character with whatever buffs they currently have as skills. However, you can turn these off at the bottom of the page. Also alot of calculators still use the monster level of 60, but with 1.0.5 all monsters in MP1 or greater are level 63. This means that your EHP suffers a little bit because of it.
Why isn't this working for me?
Are you a class other than a wizard? If so I haven't finished all the class passives / talents to make it work for other classes. This can cause problems with anything from duel wielding, to passive modifiers not being added in. It should still work with your other classes, but I can't guarantee that the numbers are accurate.
How can i report a problem?
When you encounter a problem there are some things that you can do to help me identify and fix the problem quickly. First identify what browser you're using (chrome, IE, FF), next detail the steps as if you were explaining it to a 2 year old (explaining it like "I tried it and it's not right" that doesn't help me since i don't know what isn't right). Lastly, be able to answer some questions as I might not understand the problem and may want some help figuring out the problem.
Thanks to Azliet#1154, he's helped a ton with testing and finding bugs I would have never noticed. Helped a ton with getting a quality product out for you guys.