A:

Answer

Unfortunately there is no simple answer to this question. You would need to know your compression settings and transfer rates etc.. Best thing I could suggest would be check all your settings and then google the quesiton. But to give you a ballpark, a 64Gb card at MPEG-4 AVCHD/H.264, 1920(1440) x 1080 24Mbps would give you something in the neighborhood of 320 minutes.