Quick path
Use the Camera Storage Calculator when you know camera count, video bitrate, audio bitrate, recording schedule, motion duty cycle, retention days, and drive overhead. It reports daily storage, raw retention storage, usable capacity, and total camera bandwidth.
Core formula
Add video and audio bitrate per camera, multiply by camera count, then multiply by active recording seconds.
Convert from megabits to gigabytes with GB = Mbps * seconds / 8 / 1000.
Retention capacity
Daily storage times retention days gives the raw storage requirement. Add formatting, filesystem reserve, RAID parity, failed-sector reserve, and operational headroom to estimate the usable drive capacity you should buy.
Motion recording
Motion recording only saves storage when activity is actually intermittent. A quiet hallway may write a small fraction of the day, while a street-facing camera may behave close to continuous recording.
Bitrate estimates
Resolution-based estimates are useful before devices are selected, but configured bitrate or measured bitrate is better. Night noise, rain, foliage, compression profile, GOP length, and quality settings all change real storage usage.
Production checks
- Compare the estimate with recorder reports after a representative day of footage.
- Plan spare capacity for future cameras and higher-quality profiles.
- Confirm whether the recorder reports decimal TB or binary TiB before matching drive labels.