Originally Posted by TidalWave

500-600mbps.

as has been repeated many times on this board, 1Mbps can equal a varying amount of actual transfer (GB's) based on what your traffic patterns are like.

If you push 1Mbps FLAT 24x7, without ever going below or above 1Mbps ever in an entire month, then its 320GB.
However, no one does does that.

You will in real life see about 150-200GB transfer per 1Mbps of bandwidth.