Ppl often ask me about the nisaab (& therefore the zakaat) on Bitcoin. The easiest way to see the nisaab is to go to trading view and type the following:

XAUUSD*2.733/BTCUSD

You can copy/paste that if you want, & it will show you how much coin you need to be above the nisaab.

Once you have that value, count 355 days from that point, & if you have stayed above the daily value you see on the side, then you pay zakaat. Not on ramadhaan, but 355 days from the moment you were above that line (assuming you have no other money). Then just pay 2.5% from that.