A 16GB card will hold about 2 to 2.5 hrs. hrs of 1080p/30fps video. More specifically:
- 1080p @ 30fps video and 720p/60fps use about 1 GB of space per 8 minutes of video.
- 720p @ 30fps uses about 1GB of space for each 15 min. of video footage.
- 960p @ 30fps uses about 1GB for 13 min. of video.