Zakat is one of the five pillars of Islam: 2.5% of the wealth you have held for a full lunar year, once that wealth is above the nisab. The calculation has four steps:
- Add up your zakatable assets: cash, gold, silver, investments and money owed to you, plus business cash, receivables and inventory for sale.
- Subtract the debts and bills that are due now.
- Compare the result with the nisab, using today's price of gold or silver.
- If it is at or above the nisab, multiply it by 2.5%.
For a business, the numbers come straight from the balance sheet, which is why clean books make zakat far easier. If your books aren't up to date, the figures you enter here are only as good as your records.