What size NVR should I buy for 12 cameras?

A 16-channel NVR. Never buy exactly the channel count you need today — the industry rule of thumb is 25% spare capacity, because camera counts only ever grow and replacing a recorder costs far more than the extra channels did.

What is NVR incoming bandwidth and why does it matter?

It's the total video throughput the recorder can accept, e.g. 80, 160 or 320 Mbps. If your cameras' combined bitrate exceeds it, streams drop frames or disconnect — a spec sheet detail that catches many 4K upgrades.

Should I use an NVR with built-in PoE ports?

PoE NVRs simplify small installs — cameras plug straight into the recorder. For larger systems a separate PoE switch is better: more power budget, easier troubleshooting, and cameras stay online if the NVR is serviced.

NVR Channel Planner

Enter your cameras and settings to get the recorder you should actually buy: channel count with spare capacity, the incoming bandwidth spec to check on the datasheet, and the PoE budget if the NVR powers the cameras.

Camera system

Number of cameras (today)

Resolution

Frame rate (fps)

Codec

Spare capacity

Camera power

Recorder to buy

—

Channels needed with spare—

Total camera bitrate—

Incoming bandwidth spec to look for—

PoE budget needed (NVR ports)—

Storage for 30 days—

Fine-tune retention and recording mode in the storage calculator.

What do you need next?

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The three specs that get missed on NVR datasheets

Incoming bandwidth. A "32-channel" recorder rated at 160 Mbps can't actually record 32 modern 4 MP cameras at full quality (they'd need ~280 Mbps). Channel count and throughput are separate limits — check both.
Decoding capacity. Recorders can usually record more than they can display. If a site needs many live views on a monitor wall, check the decode spec (e.g. "2 × 8 MP live").
PoE budget on PoE NVRs. Built-in ports share a small budget (often 80–130 W). Eight IR cameras at 12 W already stress a 100 W budget on cold nights.

Frequently asked questions

What size NVR for 12 cameras?

16 channels — always leave ~25% spare. Camera counts only grow, and swapping recorders costs more than the spare channels.

What is incoming bandwidth?

The total video throughput a recorder accepts (80/160/320 Mbps are common tiers). Exceed it and streams drop frames.

PoE NVR or separate switch?

PoE NVRs are great up to ~8–16 cameras. Bigger systems do better with a dedicated PoE switch: more power, cleaner troubleshooting, cameras stay up during recorder service.

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