Question: How do we calculate one fortieth of the wealth that is due Zakah? Can you explain with an example?
One fortieth of the wealth is the 2.5% of the wealth that remains after you subtract your basic needs and debts from your total wealth. You must give out this amount unless it is below the amount of nisab (85 grams of gold or equal amount of money, commodities).
For example, if you have been holding an amount of 10,000$ free of any needs and debts in the last one year, you must give 250$ as Zakah from it.
This calculation is about money (either banknotes, gold or silver) and commodities. Zakah of the agricultural products and animals are calculated according to the specific nisab amounts that are due for them.