Security camera bandwidth calculator
Enter your cameras and your internet upload: this CCTV bandwidth calculator gives the Mbps the cameras send to the recorder, the upload that remote viewing and a cloud copy need, and whether the site's connection carries it.
Examples, not measurements. Pick the closest, then change anything.
From the recorder's spec sheet. The three sheets in our NVR glossary entry list 80, 160 and 320 Mbps for 8, 16 and 32 channels.
Use a speed test from a wired port in the closet at the busy hour, not the plan's download speed. Typical: keep half free, as in our guides, for registers, phones, Wi-Fi and backups.
A sub stream is the small copy apps use for grids, an example 0.5 Mbps each.
Advanced assumptions
Typical: 10, the guide's example. Used for cloud event clips only.
Typical: 4. One person walking in sets off the sidewalk, street door, mailbox and lobby cameras at once.
Typical: 0.5, an example 640 × 360 copy. Read yours in the camera's stream settings.
Typical: 5.1 percent on full-size Ethernet frames, 1,460 bytes of data in every 1,538. Off by default, as in the cloud and remote viewing guides; a speed test already reports data after headers.
48Mbps from 12 cameras into the recorder
30% of the 160 Mbps recorder rating
8Mbps of upload needed, of 10 usable
Fits, using 80% of the usable upload
- Remote viewing
- 0 MbpsNobody watching
- Cloud upload
- 8 Mbps2 cameras all day
- Cameras the upload carries to the cloud all day
- 2at 4 Mbps a camera
- Sent off site
- 86.4 GB a dayabout 2.6 TB a month
- Phone data, one viewer
- 900 MB an hour2 Mbps × 3,600 s ÷ 8, if one person watches
- Gigabit link to the recorder
- 5% used48 of 949 Mbps after headers
An estimate from the inputs above; a site survey sets the real numbers.
- Street door and lobby: 4 Mbps (your figure) × 2 = 8 Mbps
- Other cameras: 4 Mbps (your figure) × 10 = 40 Mbps
- Into the recorder: 8 + 40 = 48 Mbps, 30% of the 160 Mbps rating; 160 ÷ 4 Mbps a camera = 40 cameras fit
- Usable upload: 20 Mbps × 50% for cameras = 10 Mbps
- Remote viewing: nobody watching, 0 Mbps
- Cloud all day: 2 cameras, 8 Mbps around the clock
- Upload needed: 0 + 8 = 8 Mbps average, 8 Mbps at the busiest moment, against 10 usable
- Cloud all day at 4 Mbps a camera: (10) ÷ 4 = 2 cameras
- Sent off site: 8 Mbps × 86,400 s ÷ 8 ÷ 1,000 = 86.4 GB a day
How to use the security camera bandwidth calculator
- Pick the closest example, then make one group for each kind of camera, and choose whether it is copied to the cloud.
- Enter the recorder's rated incoming bandwidth from its spec sheet.
- Enter the upload you measured at the site and the share you want to keep free for the business.
- Set how many people watch remotely at once, how many cameras each has on screen and which stream. The results show whether each pipe fits.
How the CCTV bandwidth calculation works
There are two pipes, and they are sized separately. Inside the building, an IP camera streams to the recorder all the time, even when it records only on motion, so the recorder takes every camera at its full bitrate. Over the internet, only what you send leaves the site: remote viewing while someone watches, and any cloud copy.
into the recorder = sum of (bitrate × cameras)
usable upload = measured upload × share not kept free
upload needed = cameras on screen × stream bitrate × people + cloud video
These are the sums in our guides to cloud storage vs a local NVR or DVR and to remote video for several sites, worked together. The constants:
- Example bitrates. At 15 fps with H.264: 1080p 3 Mbps, 4MP 5 Mbps, 4K 8 Mbps, with H.265 at about half, from the published comparison of the two codecs. Above 15 fps the bitrate scales with the frame rate. A sub stream is an example 0.5 Mbps.
- Event clips. The average is the cameras' bitrate times the share of the day with activity. The burst is the cameras that trigger together, all at full bitrate.
- Headers. A full Ethernet frame carries 1,460 bytes of data in 1,538 on the wire, 94.9 percent, so a gigabit link carries about 949 Mbps of video.
- Upload. The FCC's 2024 broadband benchmark is 100 Mbps down and 20 up; many plans upload far less than they download.
Worked example: a 12 camera walk-up with a cloud copy
Twelve cameras at an example 4 Mbps each record to an NVR in the cellar. The building uploads 20 Mbps, and keeping half free leaves 10 Mbps for cameras.
- Into the recorder: 12 × 4 = 48 Mbps, 30 percent of a 160 Mbps rating.
- Every camera to the cloud all day: 48 Mbps against 10 usable, 38 Mbps over. The upload carries 10 ÷ 4 = 2 cameras.
- Event clips at 10 percent activity: 4.8 Mbps on average, but a 16 Mbps burst when 4 cameras trigger at once, so clips queue.
- A cloud copy of the 2 entrance cameras only: 8 Mbps steady, 80 percent of the usable upload. It fits, and the NVR still records all 12.
Typical camera bandwidth
| Stream | Example bitrate | 4 cameras on screen | Phone data an hour |
|---|---|---|---|
| Sub stream | 0.5 Mbps | 2 Mbps | 225 MB |
| 1080p main | 3 Mbps | 12 Mbps | 1,350 MB |
| 4MP main | 5 Mbps | 20 Mbps | 2,250 MB |
| 4K main | 8 Mbps | 32 Mbps | 3,600 MB |
Common bandwidth mistakes
- Sizing to the plan's download speed. Remote viewing and cloud recording use the upload, often the smaller number.
- Main streams in a grid. Six 4MP main streams need about 30 Mbps; six sub streams need about 3.
- Counting only the average for event clips. Several cameras trigger together, and the burst is what queues.
- Leaving nothing for the business. Registers, phones and backups share the upload.
- Buying a recorder on channel count alone. Sixteen channels rated for 160 Mbps take only ten cameras at 16 Mbps.
Security camera bandwidth questions
How much bandwidth does a security camera use?
It depends on resolution, codec, frame rate and the scene. Our example figures at 15 fps with H.264 are 3 Mbps for 1080p, 5 Mbps for 4MP and 8 Mbps for 4K, about half that with H.265 and up to double at 30 fps. Your recorder shows each camera's real bitrate.
How much upload speed do I need for security cameras?
Only what leaves the building counts: remote viewing and any cloud copy. Four sub streams at an example 0.5 Mbps need 2 Mbps for one viewer, and four 4MP main streams at 5 Mbps need 20 Mbps. Then leave room for everything else; our guides keep half the upload free.
How many cameras can upload to the cloud at once?
Divide the usable upload by the bitrate per camera and round down. A 20 Mbps upload with half kept free leaves 10 Mbps, enough for two cameras at an example 4 Mbps streaming all day. Event clips stretch that on average, but bursts still queue.
Do security cameras use bandwidth when nobody is watching?
Inside the building, yes: an IP camera streams to the recorder all the time, so the recorder and the switch carry every camera's full bitrate. The internet upload carries only what you send off site, which is nothing when nobody is watching and there is no cloud copy.
Does motion recording reduce bandwidth?
It reduces storage, not the stream to the recorder in most camera systems, because the camera keeps streaming so the recorder can keep the seconds before a trigger. Cloud event clips do cut the average upload, but several cameras triggering together still burst.
How much bandwidth can a 16 channel NVR take?
Read it on the spec sheet; the three sheets in our NVR entry list 10 Mbps a channel, 160 Mbps for 16 channels. Twelve 4K cameras at 30 fps on H.264, an example 16 Mbps each, need 192 Mbps, so only 10 fit. On H.265 at 8 Mbps all twelve fit at 96 Mbps.
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