Storage and bandwidth for IP cameras — with codec comparison and disk planning.
24/7 = 100 %. Motion-only recording lands at 20–50 % of the time depending on the scene.
| Speicher pro Kamera und Tag | — |
|---|---|
| Speicher pro Tag (alle Kameras) | — |
| Speicher für die Aufbewahrungsdauer | — |
| Dasselbe in binär (TiB) | — |
| Live-Bandbreite | — |
| Schreibrate auf die Platten | — |
🎥 Storage planned? Then check throughput, capacity and UPS.
Ask the vendor calculators about four cameras and 30 days of retention and you get astonishingly different answers. In one documented case four calculators returned 1.69 TB, 5.80 TB, 8.01 TB and 22.95 TB for identical parameters — a factor of 13. The reason is always the same: the calculators make assumptions about bitrate, codec and motion that they do not disclose.
Storage per camera and day = bitrate × 86400 ÷ 8 ÷ 1000 (bitrate in Mbit/s, result in gigabytes). Everything else is multiplication: by camera count, by retention days, by recording share, plus a small allowance for filesystem and container overhead.
Example: eight cameras at 3 Mbit/s with 5 % overhead produce 272 GB per day. Over 30 days that is 8.16 TB (decimal) or 7.43 TiB. Recording on motion only, assuming 40 % of the time, brings it down to 3.26 TB — which is why the recording share is the second most important figure after the bitrate.
You are planning video surveillance — for a home, an office or a school campus — and want to know which disks belong in the NVR. Or you inherited an existing system and wonder why the disk fills up after two weeks when the vendor calculator promised three months. Use this calculator in two passes: first with datasheet values for the rough plan, then with the bitrate actually measured in the NVR interface for sign-off.
Enter the number of cameras and pick resolution and codec — the calculator suggests a market-typical bitrate for that combination.
Overwrite the bitrate with the value your camera really delivers. The NVR interface shows it per channel; a look at the stream helps as a fallback.
Set retention and recording share: 100 percent for continuous recording, 20 to 50 percent for motion-triggered recording in a quiet environment.
Choose disk size and configuration below. Mirrored systems need twice the disk count — the calculator shows both cases separately.
Four 4 MP cameras at 3 Mbit/s, continuous recording, 30 days, 5 percent overhead: 136 GB per day, just under 4.1 TB in total. Switching from H.264 to H.265 halves that to 2.04 TB — which is exactly why the codec sits at the top of the form and not in the small print. For disk planning that means a single 8 TB disk, or two when mirrored. If you also want to check the network, the live bitrate sum is right there — twelve megabits per second is nothing for a gigabit network.
As a start: 2 MP with H.265 around 2 Mbit/s, 4 MP around 3 Mbit/s, 8 MP around 5 Mbit/s — double each value for H.264. The authoritative figure, however, is the bitrate your camera actually produces in the configured scene.
Because they assume different bitrates, motion shares and overheads, and rarely disclose them. This calculator shows the formula with your numbers filled in — so any deviation is explainable instead of mysterious.
Audio is negligible at the usual bitrates (64 to 128 kbit/s per channel) and is covered by the overhead allowance. If you record audio, raise the overhead to 8 to 10 percent.
Technically yes, practically rarely wise: if the disk dies, all recordings are gone. For systems whose footage may need to hold up as evidence, mirroring is the cheaper insurance — it costs exactly twice the disk count.
Add the bitrates of all channels plus headroom for clients and remote access. Eight cameras at 3 Mbit/s mean 24 Mbit/s of continuous load — trivial on a gigabit network, but a bottleneck over Wi-Fi or VPN.
The formula follows standard storage maths (bitrate × time); the bitrate guide values match common H.264 and H.265 practice. The anecdote about contradictory vendor calculators comes from a discussion in r/selfhosted / r/homelab (thread "Trying to determine storage needed for security cameras", 2025). More in the portfolio: IOPS calculator, capacity converter, RAID calculator, power cost calculator.
📏 Continue with the IOPS calculator — or the capacity.