Zakat is one of the five pillars of Islam and is a mandatory charitable contribution based on a percentage of a Muslim's surplus wealth.
The key to calculating Zakat is the Nisab. Nisab is the minimum amount of wealth a person must possess for a full lunar year before Zakat becomes obligatory. This is typically measured in the value of gold (87.48g) or silver (612.36g).
Zakat is calculated at 2.5% of your total qualifying assets, including cash, gold, silver, and business merchandise, minus any immediate debts.