Nisaab is calculated by adding up the monetary value of all assets such as gold, silver and foreign exchange. If it is equal to or greater than the minimum nisaab specified in the table above, zakat is due at the rate of 2.5%. Payment of zakat is obligatory on excess wealth that is equal to or greater than the nisaab value possessed for a full Islamic year. If this wealth decreases during the year and increases again until it reaches the value of nisaab before the end of the year, then zakat must be calculated on the total amount owned at the end of the year.