Security cameras keep footage for as long as their storage allows before the oldest recordings are overwritten: typically 7 to 30 days for home systems and 30 to 90 days for businesses, but your real number is set by the hard drive size, the number of cameras, the resolution and whether you record all the time or only on motion. As a worked example, 4 cameras recording continuously at 4 MP onto a 1 TB drive keep about 6 days. With motion-only recording that rises to roughly 19 days. The tables below let you size your own system.
PCBy the Pixl Canada install team. Updated . 7 min read.
- Days of footage by drive size, cameras and resolution
- One-line formula you can reuse
- Where the 7, 30 and 90 day numbers come from
- How to check your own recorder
How long do security cameras usually keep footage?
Home systems typically keep about 7 to 30 days, and businesses about 30 to 90 days, according to vendor sources such as Solink and Ajax. Thirty days is often given as a sensible minimum for a business. Regulated sites such as banks and hospitals may keep footage far longer. These are vendor figures, so treat them as a guide, and note that local legal requirements can override them.
| System | Typical retention | What sets it |
|---|---|---|
| Home WiFi camera with cloud plan | 7 to 30 days | The plan tier you pay for |
| Home wired system with a recorder | 7 to 30 days | Drive size, cameras, resolution |
| Small business | 30 to 90 days | Your own policy and storage |
| Regulated sites | Months to a year or more | Industry or legal requirements |
What is the formula for how long a recorder keeps footage?
Each video stream uses data at its bitrate. One megabit per second (1 Mbps) recording non-stop equals 10.8 GB per day. Multiply by your number of cameras, then divide your drive size in gigabytes by that total.
- Days of footage = drive size in GB ÷ (cameras × Mbps per camera × 10.8)
- Planning bitrates used on this page: 2 Mbps for 1080p, 4 Mbps for 4 MP, 8 Mbps for 4K
- Real bitrates vary with the camera’s compression, frame rate and scene, so check your own cameras
| Resolution | Planning bitrate | GB per day per camera |
|---|---|---|
| 1080p (2 MP) | 2 Mbps | 21.6 GB |
| 4 MP (2K) | 4 Mbps | 43.2 GB |
| 4K (8 MP) | 8 Mbps | 86.4 GB |
How many days does each drive size keep?
These tables assume every camera records continuously at the planning bitrate for its resolution. They show why higher resolution and more cameras shorten retention so quickly.
| Cameras | 2 TB drive | 4 TB drive | 8 TB drive |
|---|---|---|---|
| 4 cameras | 11.6 days | 23.1 days | 46.3 days |
| 8 cameras | 5.8 days | 11.6 days | 23.1 days |
| 16 cameras | 2.9 days | 5.8 days | 11.6 days |
| Resolution | Days |
|---|---|
| 1080p (2 MP) | 23.1 days |
| 4 MP (2K) | 11.6 days |
| 4K (8 MP) | 5.8 days |
So to keep 30 days from 8 cameras at 4 MP, you need roughly 10 TB. Our 4K security camera guide explains when the extra resolution is worth the storage.
How much longer does motion-only recording keep footage?
Motion-only (event) recording stores clips only when something moves, so it uses far less storage. If cameras record about 30% of the time, retention is roughly 3.3 times longer. That is a planning assumption: a camera facing a busy street will record much more than one facing a quiet side yard.
| Cameras | 1 TB | 2 TB | 4 TB |
|---|---|---|---|
| 4 cameras | About 19 days | About 39 days | About 77 days |
| 8 cameras | About 10 days | About 19 days | About 39 days |
| 16 cameras | About 5 days | About 10 days | About 19 days |
The trade-off: motion-only can miss the moments just before an event if the pre-record buffer is short, and tampering is harder to spot. Many businesses choose continuous recording on key cameras and motion on the rest.
How do you check how many days your own recorder holds?
- Open the recorder’s menu or app and find the storage or HDD page.
- Read the drive size and the recorded time range if it shows one.
- Play back the oldest clip. The date of the oldest recording tells you your real retention.
- Compare it with your target. If the oldest clip is only a week old and you need 30 days, add storage or lower the bitrate.
- Turn on overwrite warnings if your recorder supports them, so you know before a drive fills.
Cloud cameras are simpler: your plan sets the days. See cloud storage vs a local NVR and NVR vs DVR. Footage you hand to police is covered in giving police your camera footage.
Security camera footage retention: frequently asked questions
How long do security cameras keep footage?
Typically 7 to 30 days for home systems and 30 to 90 days for businesses. The real number depends on storage size, cameras, resolution and recording mode.
How long does 1 TB last for security cameras?
For 4 cameras at 4 MP recording continuously, about 6 days. With motion-only recording at 30% activity, about 19 days. Fewer or lower-resolution cameras last longer.
Can I get CCTV footage from a year ago?
Only if the system was set to keep it. Most recorders overwrite the oldest footage when the drive fills, so a year-old clip usually no longer exists.
Does a bigger hard drive keep footage longer?
Yes. Doubling the drive doubles the days, all else equal.
How can I make footage last longer without a bigger drive?
Use motion-only recording on quiet cameras, lower the resolution or frame rate where detail does not matter, and use efficient compression such as H.265 if your cameras support it.
How long should a business keep footage?
Many businesses use 30 days as a minimum. Check your industry and legal requirements. Pixl gives a free written quote for wired CCTV sized to your retention target.
Want a system sized for your retention target?
Tell us how many cameras and how many days you want to keep. Wired CCTV quotes are free, and you pay after the job.
NVR vs DVR
4K security cameras
How many cameras do I need?
Business CCTV storage calculator
Sources and method. Retention ranges: vendor sources including Solink and Ajax. Storage figures are our own arithmetic: 1 Mbps = 0.125 MB/s = 10.8 GB per day. Bitrates of 2, 4 and 8 Mbps are planning assumptions for 1080p, 4 MP and 4K, not measurements, and the 30% motion figure is an assumption. Your cameras’ actual bitrate will differ. Drive sizes use 1 TB = 1,000 GB.
About Pixl Canada. Pixl Canada is an installation company based in Edmonton, Alberta, serving cities across Canada with TV mounting, security cameras, appliance installation and smart home setup. Call or text (587) 899-7495. Open Monday to Saturday 8am to 8pm and Sunday 9am to 7pm.