The next round is on the Full Moon of September (September 6, 2017 at 07:02 UTC):
BTC to bytes: 1 BTC of proven balance gives you 6.25 MB (0.00625 GB)
BTC to blackbytes: 1 BTC of proven balance gives you 2.1111 * 6.25 million blackbytes (money supply of blackbytes is 2.1111 times more than that of bytes)
Bytes to bytes: 1 byte on any Byteball address gives you 0.1 new bytes
Bytes to blackbytes: 1 byte on linked Byteball address gives you 0.21111 blackbytes

Putting this another way, to receive 1 GB from the distribution, you need to already hold 160 BTC or 10 GB.  These same holdings also give you 2.1111 GBB (giga-blackbyte).