How do I calculate how much that is. (What is it approximately?)
Can I deduct from that the share of the house and the furniture etc that I have to leave her?
Answer: 200 Zekukim Kesef Tzaruf comes to 2784 grams of silver at their value when going to Beit Din. Nowadays, the usual custom is to go to Beit Din and there the woman forfeits her rights to the payment of the Ketuba and they split the possessions.