Here is simple calculator for forex traders, to simplify and quickly compute lot size according to desired amount of risk and market activity.
It's Excel 2010 spreadsheet and depends on metatrader 4 DDE server to update live quotes into the book itself, so you don't have to worry about much typing.
Calculating is easy once you acquire all information needed for input.
The book contains help page to quickly introduce you how to do setup and use it.
Download here
Updates:
2nd improved version of the book has been uploaded 12/31/2014