The authentic Sunnah states that the zakah on gold and silver is one quarter of one tenth, i.e., 2.5%. A similar rate applies to trade goods and currency nowadays

The one who has any zakatable wealth must pay Zakah on it, when one year has passed since he acquired it, even if he has debts, according to the more correct of the two scholarly opinions. Prophet Muhammad used to command his agents to take Zakah from those who owed Zakah, and he did not tell them to ask them whether they had any debts or not.