Can you tell me why there is no Calculator? Because price is change every 10-30seconds so how i will know how much XMR are in BTC??
And tell me how much i will need to wait?
You can see the indicative price at any moment.
You can enter your desired BTC amount, and the website will tell you how many XMR you need to send (and also the exact price that you will get).
Conversion is instant for orders below 0.1 BTC. Above that you will wait 1-3 Monero confirmations depending on your amount, that is 2-6 minutes on average.