ZAKAT is one of the five fundamental pillars of Islam, mandatory on all muslims who are of eligible wealth. Zakat is due from and payable by a person on his wealth (and not his income), which has remained with him/her for one Islamic year. It is difficult to calculate the completion of one year on each item of wealth, because purchase dates may vary. To overcome this difficulty, a practical method is to fix a date (e.g. 1st of Ramadhan), compute your total wealth on that date and calculate Zakat, there on.
This spreadsheet is a humble attempt at making the calculation process simple and consolidated, for all muslims who are fortunate to be worthy of paying Zakat.