I purchase land for resale in future by 10-15 years and every year value of land is increasing... for example: last year if the value of land is Rupees 500000/- which paid zakat @ 2.5% and this year it is increase to rupees 600000/- So please advise me shall I pay zakat in rupees 600000/- or increase in the value of land by rupees 100000/-
In the Name of Allah, The Most Gracious, The Most Merciful.
When you pay zakat, you have to pay 2.5% of that which you own. So if you have 100,000 dollars, you have to pay 2,500 dollars AT LEAST. You can pay more if you want, but the extra you give is considered as "sadaqa", not as zakat.
As for your question; you have to give 2.5% of all your wealth the moment you give zakat. So if you decided to give zakat tomorrow, and everything you own is worth one million (right now), then you have to give 2.5% of what it's worth now, so 25 Thousand (of one million).
In your case, you have to pay 2.5% of 600k Rupees. So yeah, you always have to take today's price.
I'm not a scholar, so if someone disagrees with me, and comes with proof that I'm wrong, please share it, so that we may benefit.
Allah knows best.