About this NVR Storage Calculator
Security camera storage depends mostly on bitrate, camera count, recording hours, and retention. This calculator estimates the storage needed for an NVR or surveillance archive.
Who this calculator is for
- Home and business users sizing camera storage.
- Security installers estimating NVR drive capacity.
- IT teams planning retention for video surveillance.
When to use it
- Estimate drive capacity before buying an NVR.
- Compare 24/7 recording against scheduled recording.
- Check how retention days affect storage requirements.
How to use this calculator
- Enter camera count and average bitrate.
- Enter recording hours per day and retention days.
- Add an overhead buffer for filesystem, metadata, and bitrate variation.
- Review required TB and daily storage volume.
Key assumptions
- Bitrate is treated as an average sustained Mbps value.
- 1 TB is calculated as 1024 GB for capacity planning.
- Calculations run locally and do not process video.
Accuracy and testing
Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.
How this calculator works
Daily GB = Cameras x bitrate Mbps x recording hours x 3600 / 8 / 1024. Required TB = Daily GB x retention days x (1 + overhead percent) / 1024.
Daily GB = cameras * bitrate Mbps * recording hours * 3600 / 8 / 1024. Required TB = daily GB * retention days * (1 + overhead percent / 100) / 1024.
Inputs explained
Camera count
Number of cameras recording to the NVR.
Bitrate
Average video bitrate per camera in megabits per second.
Recording hours
Hours per day each camera records. Use 24 for continuous recording.
Retention days
How long video should remain available before being overwritten.
Understanding your results
The required storage is an estimate. Real usage varies with codec, scene motion, resolution, frame rate, variable bitrate, audio, and NVR formatting overhead.
Example scenarios
Small office NVR
8 cameras at 4 Mbps for 24 hours/day and 30 days needs about 10 TB before overhead.
Key Features
- Instant Calculation
- Private & Secure
- Mobile Optimized
Tips & Best Practices
- Use actual camera bitrate settings when available.
- Motion-heavy scenes and higher frame rates can increase storage.
- Add more overhead for variable bitrate cameras and long retention periods.