Best NVR Recorder UK 2026: Size, Storage and PoE Guide

The best NVR recorder is the one whose channel count, total bitrate ceiling and drive bays cover your cameras and your retention period with room to spare, so settle those three numbers before you look at brands. Count your cameras, add spare channels for growth, then check that the recorder's incoming bandwidth exceeds the sum of every stream's bitrate. The storage figures in this guide assume constant-bitrate recording, so motion-only recording and smart codecs such as H.265+ will use less disk than the table shows.

The best NVR recorder is the one whose channel count, total bitrate ceiling and drive bays cover your cameras and retention period with spare capacity. Brand comes after those three numbers, and the storage figures in this guide assume constant-bitrate recording, so motion-only recording and smart codecs will use less.

1. What size NVR recorder do you need for IP cameras?

Count your cameras, add spare channels, then confirm the recorder's incoming bandwidth covers the combined bitrate of every stream you plan to record.

An NVR (network video recorder) stores footage from IP cameras. Unlike a DVR, it receives streams the cameras have already encoded, usually over PoE cabling, according to Digital Camera World. That is why bandwidth, not just channel count, decides whether a recorder copes.

Channels

As general guidance, buy one size up from today's camera count. Recorders commonly come in 4, 8, 16 and 32 channels, so six cameras suit an 8-channel unit with two channels spare. Nine cameras point to 16.

Some recorders also cap total recording resolution across all channels, so check the datasheet for that limit as well as the channel number.

Checking bandwidth

Take a hypothetical 16-channel PoE recorder quoting 160 Mbps incoming and 80 Mbps outgoing. Dividing 160 by 16 gives an average ceiling of 10 Mbps per camera. Sixteen cameras each streaming at 8 Mbps total 128 Mbps, which fits with headroom (these bitrates are illustrative; use the figures from your own cameras' settings).

The outgoing figure governs remote live view and playback. At 80 Mbps, ten simultaneous 8 Mbps main-stream viewers would already exceed it, so remote viewing is usually better done on lower-bitrate sub-streams.

Aim to stay clearly below both limits rather than at them. Incoming bandwidth is also separate from the recorder's PoE power budget, which needs its own check.

2. How many TB per camera for 30 days of recording?

Per camera, TB ≈ bitrate (Mbps) × 0.45 × hours recorded per day × days ÷ 1000, so a 4 Mbps stream recorded 24/7 needs about 1.3 TB for 30 days. The 0.45 is just unit conversion: 1 Mbps works out at 0.45 GB per hour. This is arithmetic, not a test result.

Storage per camera, recording 24 hours a day

The bitrates below are assumed typical H.265 values, not measured. Every cell comes from the formula.

Assumed bitrate	14 days	30 days	90 days
2 Mbps	0.30 TB	0.65 TB	1.94 TB
4 Mbps	0.60 TB	1.30 TB	3.89 TB
8 Mbps	1.21 TB	2.59 TB	7.78 TB
12 Mbps	1.81 TB	3.89 TB	11.66 TB

Worked example: eight cameras

Assumptions: 8 cameras, each at 4 Mbps, recording 24 hours a day for 30 days.

4 × 0.45 × 24 × 30 ÷ 1000 = 1.296 TB per camera, and 1.296 × 8 ≈ 10.4 TB in total. If you want 10–20% of the drive left free, divide by 0.9 and 0.8, which gives roughly 11.5–13 TB of installed capacity.

What moves the answer

• Motion-only recording: hours per day is the variable. Six recorded hours is a quarter of the 24-hour figure, but busy scenes can erase the saving.
• H.265+ and smart codecs: these can lower the average bitrate. Read the real figure from each camera's settings rather than trusting the label.
• Night-time spikes: image noise in low light can push bitrate above the daytime value. Size to the higher figure.
• Headroom: the 10–20% free space is general guidance, not a standard.

Retention and UK GDPR

UK GDPR expects you to keep footage no longer than necessary, and it sets no single fixed period for CCTV. Pick a retention period you can justify for your site and write it into your own policy before you size the drives.

3. How many PoE ports does a PoE NVR recorder need?

Match the PoE ports to the cameras you have today, and budget separately for any camera that draws more power than a recorder port supplies. Channel count and PoE port count are not the same thing. Some 32-channel recorders offer only 24 PoE ports, so check both figures.

Working out the PoE budget

1. Take each camera's maximum power draw from its datasheet and add them up. PTZ and cameras with heaters or IR usually draw more than a basic fixed dome.
2. Compare that total with the recorder's stated PoE budget. Check the per-port limit as well, because a total that fits can still hide one camera a port can't feed.
3. Allow for cable length. Long runs lose power and can fall short of the rated distance, so check the limits on the Cat5e speed and distance page before pulling cable.

Built-in PoE or a separate switch

Built-in PoE suits a simple run where every camera sits within cable reach of the recorder and the port count covers them. A separate switch makes sense when you have more cameras than ports, when a remote building needs one uplink instead of many long runs, or when the recorder's budget is too small. Our Best PoE Switch for CCTV UK page covers the switch side.

Datasheet example: one drive or two?

Take an 8-port PoE recorder with a single SATA bay up to 6TB. Continuous recording at 1Mbps uses about 10.8GB a day, so retention in days is roughly 6,000 ÷ (total Mbps × 10.8). As an illustration only, eight cameras at 4Mbps each total 32Mbps, or about 346GB a day. That gives around 17 days on one 6TB drive.

Replace that 32Mbps with the bitrate sum from the table in section 2. If the result falls short of your required retention, you need a lower bitrate, motion-based recording or a recorder with more bays. Formatted capacity is a little under the label figure, so treat the result as a ceiling.

4. Which hard drive, bays and RAID does an NVR need?

Section 2 sets the capacity you need, but the number of bays decides whether you can add redundancy or room to grow.

Bays and per-drive caps

Every recorder has a maximum drive size per bay, and that cap limits your longest possible retention however much you want to keep. As an illustration, a single SATA bay limited to 6TB tops out at 6TB. A two-bay recorder at 6TB each reaches 12TB, or can mirror two drives instead. Check the datasheet figure before you size the system, because a drive larger than the stated cap may not be recognised.

Write load and drive type

With 8 or more streams, the drive writes continuously around the clock. As general guidance, not a benchmark, surveillance-rated drives suit that duty better than desktop drives built for intermittent use. The recorder's stated incoming bandwidth is usually the first ceiling you reach, well before the drive, so compare your total camera bitrate with that datasheet figure.

RAID, NAS and iSCSI

Mirroring (RAID 1) keeps a live copy of the footage on a second drive, which costs half your raw capacity. It protects against one drive failing, but RAID is not a backup: deletion, theft, fire or a corrupted file affects both drives. Many compact recorders have no RAID at all, so confirm it on the datasheet.

If you need more room, look for NAS and iSCSI network storage support. The HiLook NVR-108MH-D/8P, for example, lists both alongside a Gigabit Ethernet interface.

Related products

Related products from our own range:

• PoE Hikvision NVR: 32-Channel, 24 PoE Ports, 8K HDMI — Hikvision NVR with 24 PoE (power over Ethernet) ports: one cable powers and connects each camera. Up to 32 cameras; four SATA bays, up to 16TB each.
• Hikvision DS-7616NXI-K2/16P(E) 16-Channel PoE NVR — 16-channel Hikvision PoE NVR with AcuSense analytics, 16MP recording and two SATA interfaces, up to 16TB each. Prices include VAT. Free UK delivery over £100.
• Hikvision 8 Ch 1U 8 PoE 8K NVR for 32 MP Cameras — 8-channel Hikvision NVR with 8 PoE (power over Ethernet) ports for IP cameras up to 32 MP. 8K HDMI output. Two SATA bays, up to 16 TB each. DS-7608NI-M2/8P.
• Hikvision DS-7608NXI-K1/8P 8-ch PoE AcuSense 4K NVR — 8-channel PoE NVR with 4K HDMI output, AcuSense AI, facial recognition and up to 12 MP recording. Prices include VAT. Free UK delivery over £100.