Recording Capacity Calculator
How long can you keep recording before the disk fills up? Enter the free space and your recording bitrates to get hours and minutes, optionally holding some space back.
Result
- Estimated recording time
- 39 h 47 m
- Total hours
- 39.8
- Usable space
- 900 GB
- Combined bitrate
- 50.256 Mbps
838.2 GiB after the reserve.
How it is calculated
usable_bytes = disk_bytes × (1 − reserved%)
seconds = usable_bytes × 8 ÷ (video_bps + audio_bps)
Hours and minutes are derived from the total seconds. This is the inverse of the video file size calculator for a fixed amount of space.
Worked example
A 1 TB drive with 10% reserved leaves 900 GB. At 50 Mbps video and 256 kbps audio (50.256 Mbps total), that is 900,000,000,000 × 8 ÷ 50,256,000 ≈ 143,267 seconds, or about 39 hours 47 minutes.
Assumptions and limits
- Reserved space is optional but wise. Drives slow down and some recorders fail when nearly full, and the operating system needs room to work.
- Constant bitrate assumed; variable-bitrate recordings may last longer on simple scenes.
- Container overhead is not included, so real capacity is slightly lower.
- Choose GiB/TiB if your operating system reports free space in binary units, otherwise GB/TB. Picking the wrong one is an error of about 7% at the gigabyte scale and about 10% at the terabyte scale.