Security
How many days of camera recording fit on 1 TB?
Recording tables for 1–8 TB disks and a calculator for retention days or storage capacity with 2, 4 and 8 MP cameras.
A 1 TB disk can store approximately 27.8 days from one 4 MP camera, or 6.9 days from four identical cameras. There is no single retention period for every system: camera count and the amount of video each camera produces matter. Use the tables and calculator to estimate storage for your home or business.
These are typical-value estimates; results vary with scene, night vision, movement and settings. Check your cameras' actual bitrate before choosing a disk. These figures do not guarantee retention.
What changes recording retention?
- Resolution: more megapixels allow more detail but usually require more data to preserve it.
- Codec: these estimates use 2, 3 and 6 Mbps for 2, 4 and 8 MP in H.265; H.264 uses 4, 6 and 12 Mbps respectively. These are calculation assumptions, not fixed ratios for every device.
- FPS: the reference is 15 frames per second. The calculator scales typical bitrate in proportion to FPS as an approximation; a configured or measured value is preferable.
- Continuous recording stores all 24 hours. Motion recording stores triggered periods; actual recorded time depends on activity and on pre-event and post-event recording.
Calculate days or required disk capacity
Choose identical cameras, resolution, codec and FPS. If you know your camera's bitrate, enter it in Mbps: it is used directly at your chosen FPS. The reverse mode calculates TB for your target days with the same 10% disk reserve.
Recording calculator
Typical-value estimates; results vary with scene, night vision, movement and settings. Inputs assume cameras with the same configuration.
Approximate FPS adjustment: typical bitrate × FPS / 15. A known bitrate overrides this estimate: enter the value measured/configured at your chosen FPS.
Recording days with 1, 2, 4 and 8 TB
All cells show days rounded to one decimal. Assumptions: H.265, 15 FPS, a moderately active scene and continuous recording. Each table covers 1, 2, 4, 8 and 16 cameras with identical settings. We reserve 10% of the disk: each decimal TB provides 900 usable GB.
2 MP · H.265 · 2 Mbps
| Cameras | 1 TB | 2 TB | 4 TB | 8 TB |
|---|---|---|---|---|
| 1 | 41.7 | 83.3 | 166.7 | 333.3 |
| 2 | 20.8 | 41.7 | 83.3 | 166.7 |
| 4 | 10.4 | 20.8 | 41.7 | 83.3 |
| 8 | 5.2 | 10.4 | 20.8 | 41.7 |
| 16 | 2.6 | 5.2 | 10.4 | 20.8 |
4 MP · H.265 · 3 Mbps
| Cameras | 1 TB | 2 TB | 4 TB | 8 TB |
|---|---|---|---|---|
| 1 | 27.8 | 55.6 | 111.1 | 222.2 |
| 2 | 13.9 | 27.8 | 55.6 | 111.1 |
| 4 | 6.9 | 13.9 | 27.8 | 55.6 |
| 8 | 3.5 | 6.9 | 13.9 | 27.8 |
| 16 | 1.7 | 3.5 | 6.9 | 13.9 |
8 MP · H.265 · 6 Mbps
| Cameras | 1 TB | 2 TB | 4 TB | 8 TB |
|---|---|---|---|---|
| 1 | 13.9 | 27.8 | 55.6 | 111.1 |
| 2 | 6.9 | 13.9 | 27.8 | 55.6 |
| 4 | 3.5 | 6.9 | 13.9 | 27.8 |
| 8 | 1.7 | 3.5 | 6.9 | 13.9 |
| 16 | 0.9 | 1.7 | 3.5 | 6.9 |
Formula and checked examples
Days = (TB × 900) / (cameras × Mbps × 10.8).
One continuous Mbps generates 10.8 GB per day: 1,000,000 bits/s × 86,400 seconds / 8 / 1,000,000,000. We use decimal TB and GB; the recorder may display capacity in different units. The 10% reserve is a planning assumption.
- One 4 MP camera with 1 TB: 900 / (1 × 3 × 10.8) = 27.8 days.
- Four 4 MP cameras with 1 TB: 900 / (4 × 3 × 10.8) = 6.9 days.
- Sixteen 8 MP cameras with 8 TB: 7,200 / (16 × 6 × 10.8) = 6.9 days.
- One 2 MP camera with 8 TB: 7,200 / (1 × 2 × 10.8) = 333.3 days.
For reverse mode: TB = (days × cameras × Mbps × 10.8) / 900. Four 4 MP cameras for 30 days require 4.32 TB under these assumptions: choose an available capacity above that value and check the recorder's limits. Round only at the end.
H.264 and motion recording
With the assumed H.264 values of 4, 6 and 12 Mbps, retention is half of the H.265 tables. Actual behavior depends on each camera's compression and configuration.
Motion recording can provide several times as much retention. Recording 25% of each day divides daily consumption by four and multiplies retention by four. The formula includes activity / 100 in the denominator; reverse mode multiplies required TB by that factor. For example, four 4 MP cameras and 1 TB provide approximately 27.8 days at 25% activity versus 6.9 days continuously. Rain, insects, night noise or a busy street may keep recording active for much longer. A 0% recording duty cycle does not give a useful retention estimate; the calculator requires a percentage above zero.
Plan the network and installation too
Storage and networking meet different needs. Read how much bandwidth IP cameras use to size links and internet upload for phone viewing.
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