Nisab, the threshold above which Zakat is compulsory on you, is the monetary value of 612.36 grams of Silver.
An alternative way to calculate the Nisab, is to base it on the monetary value of 87.48 grams of gold. Using the Gold Nisab reduces the amount of Zakat that is collected and distributed to the poor, and so, it is recommended to use the Silver Nisab instead.
Today’s Silver Nisab value is shown at the top of this page.