how do people who work as civil servant calculate their zakat?
The Required Amount (Nisab) for Zakat
The amount of gold that requires Zakat is around 92 grams, when this amount or more has remained unchanged in one's possession for one full year. The required Zakat in this case is one-fourth of a tenth (2.5%), which is approximately 2.3 grams.
Silver requires Zakat to be paid when it reaches 735 grams or more and when this amount remains unchanged in one's possession for a full year. The amount of Zakat required in this case is also one-fourth of a tenth (2.5%), which is approximately 18.4 grams.
*Cash at One's Disposal
When it is worth the amount of gold or silver that requires Zakat and when this amount remains above the Nisab value for a full year. Zakat in this case is also one-fourth of a tenth, or 2.5%.
*Items Used for Business Transactions and Commercial Purposes
This requires a fourth of a tenth (2.5%) Zakat to be paid on them, when they remain a full year without decreasing below the Nisab amount. The minimum amount of the value of business merchandise that requires Zakat to be paid is the same as gold and silver, and the merchant could use either standard to estimate how much Zakat he should pay.
When the Muslim finds any treasures hidden in his land, he is required to give a fifth (20%) of that treasure in charity as Zakat.
Mines, such as gold and silver mines, require Zakat to be paid on them whenever the minerals are discovered and extracted, just as the case with produce. Mines for extracting precious metals and minerals fall under the ruling of Rikaz and thus 1/5th (20%) Zakat is due upon them just as with buried treasure.
*Returns on Investments
If the investment is merchandizing transactions or animal products, then the Zakat for these returns on investment should be paid in addition to, and at the same time when the Zakat is paid on the principal, even if these profits did not remain for a full year. For instance, if the animal gives birth when the Zakat on the animals is due, then the owner should add all of these animals together and pay the Zakat due on all of them, and such is the case with monetary investments. When one earns money from inheritance or gifts, the Zakat becomes due if such inheritance reaches the minimum amount that requires Zakat and remains for a full year in one's possession without decreasing below the Nisab amount.
Grazing camels, grazing cows and grazing sheep and goats are eligible for Zakat payment. Each category of the above mentioned livestock animals has a set Nisab amount based upon the number of animals owned. These figures can be researched from the appropriate books of Islamic Jurisprudence.
*Fruits and Grains
When the produce is ready for harvest and the fruits become ripe, then the Zakat on them is due. Allah (S.W.T)says: "...but pay the due thereof (their Zakat) on the day of their harvest..." (6:141)
As for fruit, every type of fruit has its own standard as to when it is ripe and ready to eat. For instance, dates are ripe when they become red or yellow, while grapes are ripe when they become sweet. The amounts of fruits and grains that require Zakat is five Wasqs, each of which is sixty Sa', and a Sa' is slightly less than three kilograms. Hence, the minimum Nisab that requires Zakat on dates. raisins, wheat and barley is three hundred Sa' (or approximately 900 kg). If the crop is watered without much effort, such as by spring water or by rain, it requires one-tenth (10%) as Zakat payment. This means that half of a Wasq (90 kg) is due for every five Wasqs. If such produce is watered with effort. such as from wells or irrigation channels, it requires a half of a tenth (5%) as Zakat payment. This means for every five Wasqs, there is a quarter of a Wasq (45 kg) due for Zakat.
"On a land irrigated by rain water, or by natural water channels, or if the land is wet due to a nearby water channel, one-tenth is compulsory (as Zakat). On the land irrigated by a well. half of one tenth is compulsory (as Zakat on the yield of the land)," (Al-Bukhari and Muslim)