Zakat: Calculation

Is there a spreadsheet or can someone devise a spread sheet detailing Zakat Calculations in the modern world? Every year I find it difficult to know that what I am calculating is correct. I believe that I am not the only one who has this difficulty. Can someone detail clearly the steps to calculating Zakat due, I mean if I sat down to calculate my Zakat what discreet steps would be needed to arrive at the Zakat due figure.

Al-Salam alaykum

I know that here in South Africa there is a table that is common which makes it easy to calculate Zakah. It was drawn up by Brother Shuaib Omar - a lawyer who also studied under Mufti Taqi Uthmani. He is quite well versed in Zakah and other business laws. The table should be on the web somewhere I will try and find it. If not I will type it for the benefit of those interested Insha Allah.

Abu Usamah
Al-Salam alaykum

See this link http://www.jamiat.org.za/isinfo/zakaat_c.html for a table on Zakah.