If one has not paid Zakat for several years, how does one go about calculating it?
In the name of Allah, Most Compassionate, Most Merciful,
Zakat becomes obligatory upon an individual when he/she becomes the owner of the appointed Zakat-payable amount (nisab) for the first time in his/her life after reaching puberty. This Nisab is 612.36 grams of silver and/or 87.48 grams of gold. If one has wealth to the value of the above-mentioned Nisab, one will be known as Sahib al-Nisab, hence Zakat will be obligatory at the rate of 2.5%. Thereafter, Zakat will be payable each year at the appointed date.
It should also be remembered that Zakat is to be paid only on certain items, namely: 1) Gold and silver, 2) Cash, 3) Merchandise (i.e. items for resale), 4) Agricultural produce, 5) Livestock. As such, one will have to add the value of all these types of wealth and pay 2.5% of the total.
Therefore, if you have not paid Zakat for the previous years, you need to make a precautionary estimation as to the total wealth that was owned by you each year in the form of the items mentioned above. You need to estimate how much savings you had each year, whether the cash was at hand, in the bank, in the form of checks, financial certificates or any other form. You need to estimate how much gold and/or silver you possessed (if any) and how much business wealth (i.e items for resale) you owned.
Whatever total amount you consider to be your savings for each year, Zakat will be payable on that amount. In order to determine this correctly, you may look at your previous bank statements, your wage slips and anything else that may be of help. It would be better to pay slightly more than the amount that was estimated, so as not to pay an amount that is less than what was required. It is better to be safe and sure by paying more than the amount that was estimated.
And Allah knows best
[Mufti] Muhammad ibn Adam
Leicester , UK