How long should you keep CCTV footage? Retention and storage maths
Every recorder overwrites old video once its disks are full. Retention is simply how many days pass before that happens. Most owners never choose it. The disk size chooses for them.
The storage maths
Disk use is bitrate multiplied by time. A rough guide for one camera recording all day:
| Stream | Per day | 30 days |
|---|---|---|
| 2 Mbps (1080p, efficient codec) | about 21 GB | about 630 GB |
| 4 Mbps (4 MP) | about 43 GB | about 1.3 TB |
| 8 Mbps (4K) | about 86 GB | about 2.6 TB |
Multiply by your camera count. Eight 4 MP cameras for 30 days need about 10 TB, before any spare space.
Ways to stretch it
- Motion recording on quiet cameras, such as a back store room.
- A lower substream for cameras that only need to show presence.
- Efficient codecs where your cameras support them.
- Different retention per camera. The cash counter needs longer than the street view.
What the law asks
Under Nepal’s Privacy Act, 2075, footage is commonly read to need keeping for three months. Banks and public bodies often have their own, longer rules. Read the details in the Privacy Act and CCTV in Nepal.
Keep the important moments longer
A fixed period cannot know which clip matters. When an incident happens, export it before the overwrite reaches it. See exporting evidence that stands up.
Choose a number, then check it
Pick the days you need, multiply, and compare with the disk you have. If the answer does not fit, reduce cameras on continuous recording before you reduce days.
Questions people ask
How many days of footage should a shop keep?
At least thirty days is a safe aim for most shops, because many problems, such as a stock shortfall or a disputed refund, are noticed late. Check the figure against what your disks can hold.
Does Nepal's law set a minimum?
Nepal's Privacy Act, 2075 is read to ask for footage to be kept for at least three months. Confirm the current rule for your sector with a lawyer.
How do I keep one incident longer than the rest?
Export it, or place it under legal hold, so the normal overwrite does not delete it. See the evidence export guide.