As Zakat is one of the 5 pillars of Islam hence paying it accurately shall be very important to a Muslim. Nonetheless, if it is paid more than extra then not only it is a charity but a huge saver for yourself by assuring at least the correct amount has been paid.
It is observed that many of us fall into the mistake of calculating Zakah incorrectly resulting in less amount paid for Zakat. This can lead to the punishment of Allah Subhana Wa Ta’ala in hereafter as reported by several authentic ahadeeth of Rasool Allah Sallallahu Alehe Wassalam.
The following short video is a good tutorial in knowing how to correctly calculate your Zakat in the most easiest manner.
You may then use this beautiful interactive Zakat calculator (Zakat made simple) to calculate and pay your Zakat (courtesy of NZF):