Understanding Zakat and the nisab threshold
Zakat is one of the five pillars of Islam, an annual act of worship in which eligible Muslims give a fixed share of their qualifying wealth to those in need. It is not a donation in the casual sense and not a tax. It is an obligation owed once a lunar year on wealth that has been held above a minimum threshold, and getting the calculation right is part of fulfilling it properly. The standard rate is 2.5% of your net eligible wealth, but that rate only applies once your wealth meets or exceeds the nisab.
The nisab is the minimum amount of wealth a person must hold before Zakat becomes due. It is traditionally defined by the value of 87.48 grams of gold or 612.36 grams of silver, and the cash equivalent shifts with the market price of those metals. Because the silver-based nisab is lower, using it means more people qualify to give, which many scholars favor as it benefits recipients. If your total eligible wealth sits below the nisab, no Zakat is owed that year. If it meets or exceeds it, the full 2.5% applies to the qualifying total.
What counts toward Zakat is broader than just the cash in your account. Eligible assets generally include cash on hand and in bank accounts, gold and silver, money you have lent to others and expect back, business inventory and merchandise held for sale, and investments such as stocks held for trading. From this you subtract immediate debts and liabilities that are due. Your primary home, personal car, household goods, and tools of your trade are typically not counted, because Zakat applies to accumulated wealth, not to the things you use day to day.
There is also the condition of the lunar year, called the hawl. Zakat is due on wealth that has been in your possession for one full Islamic year and has stayed at or above the nisab through that period. A simple worked example: if your net eligible wealth is $20,000 and it has met the nisab for a full year, your Zakat is 2.5% of $20,000, which is $500. The calculator applies this same logic, checking your total against the nisab first and then computing the 2.5% only when it is due.
A respectful note: rulings on specific assets, such as retirement accounts, certain investments, or money owed to you, vary among schools of thought and qualified scholars. This tool gives you a clear, standard estimate, and consulting a knowledgeable local scholar is the right step for cases unique to your situation.