How should I Calculate Zakaat?
The amount of wealth which makes one liable for Zakat is called Nisab. The payment of Zakat is compulsory on the excess wealth which is equal to or exceeds the value of Nisab, and which is possessed for a full Islamic year. If such wealth decreases during the course of the year, and it increases again to the value of Nisab before the end of the year, the Zakat then must be calculated on the full amount that is possessed at the end of the year.
Zakaat Calculator Table
Following is a link to an example which may help you in calculating Zakaat.