How much storage does one CCTV camera use?
A single CCTV camera records a constant stream of video, and every second of that stream takes up space on a hard drive, SD card or network video recorder. How much space depends on four things: the camera's resolution, its bitrate, how many hours a day it records, and how many days of footage you want to keep.
As a starting point, one 1080p camera recording around the clock at a typical 1.2 megabits per second uses about 12.7 GB per day. That adds up to roughly 380 GB over 30 days — and that is before you add a second, third or fourth camera. Most people underestimate this by a factor of two or three, which is how they end up buying a 1 TB drive for a system that needs twice that.
The CCTV storage formula
The math behind camera storage is simple once you know the bitrate — the number of megabits per second the camera's video stream uses. Bitrate is the single biggest lever: it decides how much data each second of video contains, and everything else multiplies from there.
Storage (GB) = bitrate (Mbps) × recording hours × 3,600 ÷ 8 ÷ 1,024 × cameras × days
In words: convert the bitrate to bytes per hour (× 3,600 seconds, ÷ 8 bits per byte, ÷ 1,024 to get gigabytes), then multiply by the number of recording hours, cameras and retention days. Try it: 1.2 Mbps × 24 hours × 3,600 ÷ 8 ÷ 1,024 = 12.66 GB — which matches the tool's 12.7 GB figure almost exactly.
Storage by camera resolution
Resolution drives bitrate, and bitrate drives storage. A 4K camera can use four times the storage of a 1080p one at the same frame rate. The table below shows typical per-camera storage for 24-hour recording at common resolutions and their usual bitrates.
| Resolution | Typical bitrate | Per camera per day | Per camera per 30 days |
|---|---|---|---|
| 720p | 0.6 Mbps | ~3.2 GB | ~95 GB |
| 1080p Full HD | 1.2 Mbps | ~12.7 GB | ~380 GB |
| 2K / 1440p | 2.5 Mbps | ~26 GB | ~790 GB |
| 4K Ultra HD | 4.5–6 Mbps | ~47–63 GB | ~1.4–1.9 TB |
These are continuous-recording figures. Motion-triggered recording, which only writes when the camera detects movement, typically cuts them by 30 to 70 percent depending on how busy the scene is.
Codec choice matters too. A camera streaming H.265 (HEVC) can deliver the same picture quality as H.264 at roughly half the bitrate, which halves every number in the table. If your recorder and cameras both support it, switching the encoding is the cheapest storage upgrade available — it costs nothing and needs no new hardware.
Worked example: four cameras, thirty days
Consider a small shop with four 1080p cameras recording 24 hours a day, keeping footage for 30 days. Each camera needs 12.7 GB per day, so four cameras need 50.8 GB per day. Over 30 days that becomes 1,524 GB — about 1.48 TB.
A 1 TB drive is therefore not enough; the safe choice is a 2 TB surveillance-rated drive, which leaves headroom for overhead and a few days of slack. Drop to 720p on the two least critical cameras and the total falls under 1 TB — a useful trick when the budget is tight.
Five ways to use less storage
- Use motion detection. Cameras that record only on movement save 30–70% of storage in quiet areas such as back doors and storerooms.
- Lower resolution where it does not matter. Keep 1080p on the entrance and cash register; 720p is fine for a general overview camera.
- Reduce the frame rate. Security footage rarely needs 30 fps — 10–15 fps looks smooth enough and nearly halves the bitrate.
- Choose H.265 encoding. Modern cameras with H.265 (HEVC) compression store the same quality in roughly half the space of older H.264.
- Shorten retention where legal. If local rules allow 15 days instead of 30, you instantly halve your storage bill.
Calculate it for your own setup
Every system is different — different cameras, different hours, different retention needs. The CCTV Storage Calculator on Veltrix News does the formula above for you: enter your camera count, recording quality, daily recording hours and retention days to get an instant estimate in GB and TB.
https://veltrixnews.online/tools/cctv-storage-calculator
Frequently asked questions
How much storage does a 1080p CCTV camera need per day?
About 12.7 GB per day at a typical 1.2 Mbps bitrate with 24-hour continuous recording — roughly 380 GB over 30 days.
Is 1 TB enough for 4 cameras for a month?
Usually not. Four 1080p cameras recording around the clock generate about 1.48 TB over 30 days. A 2 TB drive is the safe minimum.
Does motion detection really save storage?
Yes — typically 30 to 70 percent, because the camera only writes when it sees movement. In busy areas the saving is smaller, so schedule motion recording or lower the resolution there instead.