CALCULATOR / STORAGE
NVR Storage Calculator for IP Cameras and Retention
Use this NVR storage calculator to estimate capacity from camera count, bitrate, recording hours, retention days, and headroom. The result must be checked against codec, motion recording, RAID, filesystem, and vendor overhead.
INTERACTIVE PLANNING TOOL
ESTIMATED DECIMAL CAPACITY
12,441.6 GB
≈ 12.44 TB before platform-specific usable-capacity checks.
Planning equation: cameras × Mbps × hours × days × 0.45, then the selected headroom. Codec, motion recording, RAID, filesystem, exports, and recorder limits can change the result.
The planning equation
For continuous recording, storage in decimal gigabytes is approximately camera count × bitrate in Mbps × recording hours × retention days × 0.45. Add headroom for filesystem, export, motion bursts, redundancy, and operational margin.
Variable or motion recording changes the average bitrate. Use measured recorder statistics when available and preserve the assumptions beside the estimate.
Worked example
Eight cameras at 4 Mbps, recording 24 hours a day for 30 days, produce about 10,368 GB before the selected headroom in this site’s decimal planning convention. With 20% headroom, the estimate is about 12.44 TB. The result is an input check, not a disk purchase recommendation.
If the average bitrate doubles, the storage estimate doubles. If the number of cameras or retention days doubles, the estimate also doubles. This makes sensitivity easier to explain than a resolution-only rule.
- Camera count: 8
- Average bitrate: 4 Mbps per camera
- Recording: 24 hours/day
- Retention: 30 days
- Planning headroom: 20%
What the number does not prove
A capacity estimate does not establish retention compliance, disk health, RAID usable capacity, recorder limits, write performance, or evidence availability. Confirm those separately with the selected platform and policy owner.
FIELD CHECKLIST
Record the result, not only the intention
- Record camera count, bitrate, recording hours, retention days, and headroom.
- Separate continuous, scheduled, event, and motion-recording assumptions.
- Check codec, RAID, filesystem, export, and recorder usable-capacity limits.
- Compare the estimate with measured recorder statistics when available.
- Record the policy owner and test storage-full and recovery behavior.
FAQ / LONG-TAIL QUESTIONS
Frequently asked questions
How do I calculate NVR storage for IP cameras?
Enter camera count, bitrate per camera, recording hours, retention days, and planning headroom. Treat the result as a decimal planning estimate and then check codec, motion recording, RAID, filesystem, exports, and recorder limits.
How much storage do 8 security cameras need?
There is no single answer without bitrate, recording schedule, retention days, codec, and headroom. Use the calculator with those assumptions and compare the estimate with the recorder’s usable capacity.
What affects CCTV retention storage?
Camera count, bitrate, resolution and codec, frame rate, motion or continuous recording, hours per day, retention days, exports, RAID or filesystem overhead, and usable-capacity rules all affect the result.