Nisab

The nisab is the minimum amount of wealth above which zakat becomes due. It is defined in the traditions of the Prophet in terms of silver and gold: 200 dirham of silver and 20 mithqal of gold. In modern weights these are most often given as 612.36 grams of silver and 87.48 grams of gold (some sources give slightly different conversions).

Gold or silver?

Silver was worth much less in comparison with gold than it was in the early days of Islam, so the silver nisab is far lower than the gold nisab. Many scholars and zakat organisations today advise using the silver nisab for cash and savings, because it leaves fewer people without the duty and benefits more poor people; others advise gold. Your own scholar decides. The calculator lets you choose.

Finding it today

Look up the price of one gram of silver (or gold) from a trusted source such as a bullion dealer or the market page of a news site, then multiply by the weight: for example, 612.36 times the price per gram of silver. Enter the price in the calculator and it does the rest.

This is a calculator and a plain explanation, not a fatwa. Schools of thought differ on what is zakatable (for example, jewellery, shares and business assets) and on how to value them. For your own case, ask a trusted scholar or a zakat office.