📹 Security Camera Storage Calculator
Plan the NVR or DVR storage your surveillance system needs. Set resolution, frame rate, recording hours, retention, and camera count to see the gigabytes and terabytes required, plus a suggested drive size.
📹 Storage you'll need
Based on 4 Mbps per camera, 24 h/day for 30 days across 4 cameras. Table bitrates assume H.264 continuous recording — H.265/HEVC roughly halves them, and motion-only recording cuts them further. A planning estimate; real footage size varies with scene motion.
It all comes down to bitrate
A camera’s storage appetite is set by its bitrate — the megabits per second it writes to disk. Resolution and frame rate drive that bitrate up, while smarter codecs like H.265 and motion-only recording pull it down. Everything else in the sum is just multiplication: seconds in an hour, hours in a day, days of retention, and the number of cameras.
The formula is storage(GB) = bitrate(Mbps) × 0.125 × 3600 × hours/day × days × cameras ÷ 1024. Size for the retention you truly need, buy surveillance-rated drives built for constant writing, and leave headroom for the cameras you’ll inevitably add.
❓ Frequently Asked Questions
How much storage does a security camera use per day?
It depends almost entirely on bitrate. A single 1080p camera at ~4 Mbps recording continuously uses roughly 42 GB per day; a 4K camera at ~16 Mbps uses about four times that. Multiply by your number of cameras and retention days to size the drive.
What bitrate should I use?
If you know your camera's configured bitrate, enter it directly. Otherwise pick a resolution and frame rate and the calculator uses a typical H.264 continuous-recording bitrate — about 2 Mbps for 720p, 4 Mbps for 1080p, 8 Mbps for 4 MP, and 16 Mbps for 4K.
Does H.265 or motion-only recording change the numbers?
Yes, a lot. H.265/HEVC compression roughly halves the storage of H.264 for the same quality. Motion-activated recording only writes when something moves, so a quiet scene can cut storage by 50–80%. The table assumes the worst case — continuous H.264 — so you'll rarely need more.
How many days of footage should I keep?
Common retention is 30 days, which is enough to review incidents you didn't notice immediately. Some businesses and jurisdictions require more. Longer retention or more cameras multiplies the drive size, so plan storage around the retention you actually need.
What drive should I buy?
The calculator suggests the next common surveillance-drive size up from your requirement. Use drives rated for continuous 24/7 write workloads (surveillance-grade HDDs), and add headroom if you plan to add cameras or increase retention later.