Hi i made this for pvp, and i also posted it in the dungeons forums, and this looks like a useful spot too, so im posting it here as well.
This is a damage calculator i made months ago when i was more into build crafting. I updated it today and included more accurate calculations, especially for estimating your damage over multiple attacks. The calculation formulas i used are basically the ones on the gw2 wiki.
Screenshot: http://postimage.org/image/8nalgnzob/
I dont have any skill coefficients besides 100b listed on there already, but with my updated skill coefficient formula they are easy to obtain. It may look intimidating at first, but its really simple and easy to use. Just follow the instructions.
If you are interested in this, let me know if you find any calculation errors or if something doesnt make sense.
The file is a protected excel sheet, which is much safer to use, and you wont inadvertently mess something up which will throw off the calculations.
I couldnt make an attachment with the excel format on the forums, so i uploaded it to depositfiles. Also google docs couldnt properly convert the file and kittened it all up.
http://depositfiles.com/files/e5434f530
Warning, 60 second wait.
Edit: For those who dont have excel, OpenOffice by Apache (free) works with excel sheets. I tested it with this file and it appears to work, though the formatting is a bit different.
http://www.openoffice.org/
Edit 2: I think i forgot to define ESD. ESD is your estimated sustained damage, the damage you are expected to do over multiple hits given your crit chance. The higher your crit chance is, the closer your ESD damage will be to critical damage.