IP Camera Bandwidth Calculator

How this calculator works

Most IP cameras stream continuously to your NVR or VMS regardless of whether they're set to record continuously or only on motion — recording mode changes what gets written to disk, not what's sent over the network. So bandwidth planning normally assumes every camera is streaming all the time.

Worked example

Illustrative only — your result depends on your own camera count, resolution, frame rate, codec and headroom. This example uses the calculator's default inputs: 16 cameras, 4MP, 15 fps, H.265, 25% headroom.

Assumptions behind the numbers

These are planning estimates based on average bitrates, not guaranteed values. Real camera bitrate varies with scene activity, codec and quality settings, the GOP / I-frame interval, and the manufacturer's own configuration — two "4MP" cameras can differ widely. When you can, check the camera's datasheet for its maximum or target bitrate, and if you know the bitrate it's actually configured to, enter it with the custom bitrate option.

Why add headroom?

A camera watching a busy scene can briefly use 2–3x its average bitrate. Headroom is an allowance for aggregate network peaks and normal variation across the whole system — cameras rarely peak at the same moment, so 20–30% on the total is a common planning margin. It is not a guarantee against one camera's worst-case instantaneous spike.

H.264 vs. H.265 bandwidth

H.265 (HEVC) typically needs roughly half the bitrate of H.264 for comparable image quality, so this calculator applies a factor of 0.5. H.265+ and other vendor smart-codec modes cut bandwidth further on scenes with little motion, and are modelled with a factor of 0.32. For a 4MP camera at 30 fps that means about 6 Mbps on H.264, 3 Mbps on H.265 and 1.92 Mbps on H.265+. Real savings depend on the camera, the scene and the encoder, so treat them as planning estimates.

Source note: the roughly 50% figure for H.265 matches what the ITU said when it announced the standard, that HEVC "will need only half the bit rate of its predecessor" (ITU press release, 25 January 2013). That was a projection by the standards body, not a measurement of CCTV streams. The H.265+ and smart-codec savings used on this page are planning estimates without a verified source, and they vary heavily with the scene.

Matching bandwidth to switch uplink speed

Each ceiling is 80% of the link speed (80 Mbps, 800 Mbps, 8 Gbps), so a link is never sized to run near its limit. The totals already include your headroom. Remember this figure is for the uplink between your PoE switch and the NVR — individual camera ports only need to handle that one camera's bitrate, which is almost always well under 100 Mbps even for 4K. It's the aggregation point (the switch-to-NVR link, or the link between stacked switches) where bandwidth adds up and needs checking.

How many cameras can a link handle?

The same formula works in reverse: cameras ≈ usable link bandwidth ÷ (per-camera bitrate × (1 + headroom)), where usable bandwidth is 80% of the link speed. The answer depends entirely on the resolution, frame rate, codec or custom bitrate you choose, so treat it as an estimate. This calculator doesn't solve for it directly — run one camera to get its per-camera bitrate, then divide. Examples at 25% headroom, rounded down:

These figures cover the uplink only. The NVR's incoming bandwidth and the switch's PoE budget often limit the camera count first.

Your NVR has its own bandwidth limit

Switch uplink capacity and the NVR's incoming (recording) bandwidth are two separate limits. Recorders publish a rated incoming bandwidth on the datasheet — it varies widely, from around 80 Mbps on entry-level units to several hundred Mbps on larger ones. Compare the total from this calculator with that rating. A gigabit network interface on the NVR doesn't mean it can ingest a gigabit of camera traffic; if the cameras send more than the rated figure, the NVR may drop frames or lower the recorded bitrate.

Remote viewing and offsite access

This calculator sizes the local network between your cameras and the NVR. Remote viewing commonly uses a lower-bitrate sub-stream rather than the full main stream, so it typically needs far less than the totals shown here. For remote access, your site's upload bandwidth and how you actually view the cameras (which stream, how many viewers) are what matter — this calculator doesn't model them.

Don't forget PoE power alongside bandwidth

Bandwidth and power budget are two separate constraints on the same switch — a switch can have plenty of bandwidth headroom left while still running out of PoE wattage if you're powering high-draw PTZ cameras or IR-heavy bullet cameras. Check your switch's total PoE budget separately from the bandwidth figure here, using the PoE Budget Calculator, and see PoE Budget Calculator: How Many Cameras Can Your Switch Run? for how the power math plays out on a real job.

Frequently asked questions

What if my cameras aren't all the same resolution?

Run this calculator once per camera group (same resolution and fps) and add the resulting Mbps figures together. Mixed installs are common, and this is more accurate than trying to average the resolutions.

Do I need to check bandwidth per camera port or just the uplink?

Just the uplink to the NVR, or between switches if you're stacking them. A single camera's own port only ever carries that one camera's stream, which is almost never a bottleneck. It's the point where all the streams combine that needs the bandwidth check.

Does PoE power capacity matter separately from bandwidth?

Yes. Bandwidth and PoE wattage are two different limits on the same switch. A switch can have bandwidth to spare while still running out of PoE budget for high-draw PTZ or IR-heavy cameras, so check both specs, not just this one.

How much bandwidth does an IP camera use?

It depends on resolution, frame rate, codec and scene. With this calculator's planning figures, a 4MP camera at 30 fps on H.264 uses about 6 Mbps, and the same camera on H.265 at 15 fps uses about 1.95 Mbps. Real bitrates vary by manufacturer, scene activity and encoder settings, so check the camera's datasheet or configured bitrate, and enter it with the custom bitrate option if you know it.

Does H.265 use less bandwidth than H.264?

Yes. H.265 (HEVC) typically needs roughly half the bitrate of H.264 for comparable image quality, and H.265+ or other smart-codec modes can reduce it further on scenes with little motion. This calculator applies factors of 1.0 for H.264, 0.5 for H.265 and 0.32 for H.265+, so a 4MP camera at 30 fps drops from 6 Mbps to 3 Mbps on H.265 and about 1.92 Mbps on H.265+. Actual savings depend on the camera, the scene and the encoder.

How many cameras can a 100 Mbps or 1 Gbps link handle?

Divide the usable link bandwidth by the per-camera bitrate including headroom. This calculator treats 80% of link speed as usable: 80 Mbps on a 100 Mbps link and 800 Mbps on a 1 Gbps link. For 4MP H.265 cameras at 15 fps with 25% headroom (about 2.44 Mbps each), that is roughly 32 cameras on a 100 Mbps link and 328 on a gigabit link. For 4MP H.264 at 30 fps (7.5 Mbps each) it is roughly 10 and 106. These are estimates for the uplink only; the NVR's incoming bandwidth and the switch's PoE budget often limit the camera count first.

Is the NVR's incoming bandwidth the same as my switch uplink?

No. They are separate limits. The uplink is the network link between your switch and the NVR. The NVR's rated incoming (recording) bandwidth is the total video data rate the recorder itself can ingest, and it is often much lower than a gigabit port's speed. Compare the calculated total with the rating on the NVR's datasheet: a gigabit network interface does not mean the NVR can accept a gigabit of camera traffic.

Is headroom a guarantee against bitrate spikes?

No. Headroom covers aggregate peaks and normal variation across the whole system, not the worst-case instantaneous spike of a single camera. A busy scene can briefly push one camera to 2–3 times its average bitrate, but cameras rarely peak at the same moment, so a 20–30% margin on the total is a common planning allowance. If you know a camera's configured or maximum bitrate, enter it with the custom bitrate option.

Does remote viewing use the same bandwidth as recording?

Not usually. Remote viewing commonly uses a lower-bitrate sub-stream rather than the full main stream, so it typically needs far less than the totals shown here. For remote access, your site's upload bandwidth and how you actually view the cameras (which stream, how many viewers) matter. This calculator sizes the local network between the cameras and the NVR and does not model remote access.

Related CCTV tools

Bandwidth is only one piece of the install. Pair this with the NVR Storage Calculator for drive space on the same cameras, the CCTV Storage Calculator if the job mixes in analog HD-CCTV hardware, and the Field of View Calculator to check coverage and identification distance before finalizing camera placement.

Related guide

For the full breakdown of switch uplink overload and PoE budget mistakes — the two checks that fail most often even when bandwidth looks fine — see IP Camera Bandwidth: Why the Switch (and PoE Budget) Fail Before the Network Does.

Found a wrong result on this calculator? Send feedback →