Our guide to zakat is Imam Mohammad Bashar Arafat, a scholar, chaplain, and interfaith leader in Baltimore, Maryland.
Imam MOHAMMAD BASHAR ARAFAT: Zakat is obligatory on the Muslim, each Muslim, who is earning income. They have to give from the savings of what they have from last year to this year -- they calculate and they give two and a half percent of what they earn. But that's the minimum.
The whole concept of money is considered in Islam as a gift from Almighty. As he gave it to you, he made a portion of it belong to the poor. So the poor has right in your money.
Zakat is always connected in the Qur'an with prayer. As Allah says, "Establish prayer and give zakat. Give in charity." And it's mentioned 82 times in the Qur'an, that connection, to show the relation between prayer, salaat, and giving. You cannot claim that you are a true believer without helping others. The whole religion of Islam is based on helping others. 
