Camera Storage & Bandwidth Calculator

Why the bandwidth number matters as much as the storage

Most camera quotes get the drive size roughly right and never mention the network. Then thirty cameras go onto the same switch as the tills and the point-of-sale system starts timing out at 4 p.m. The peak figure above is what every camera streaming at once puts on the link to the recorder — plan the uplink and the VLAN around it, not just the disks.

Where these numbers come from

Baseline bitrates are the typical published figures for H.264 at 30 fps with medium scene activity, in line with what Avigilon, Rhombus and Meraki quote for their own hardware. Then:

• Codec. H.265 lands around half the bitrate of H.264 for the same picture. Smart-codec modes, which drop the bitrate hard on static scenes, get to roughly a third.
• Frame rate scales sub-linearly. Halving fps does not halve the file, because keyframes and static background still have to be encoded. We use a 0.65 exponent, which tracks real recorder behaviour closely.
• Scene activity. A storeroom compresses far better than a car park with trees moving behind it. This is the single most under-estimated factor in camera sizing.
• Storage is decimal GB and TB — 10¹² bytes — because that is how drives are sold. A "4 TB" drive formats to about 3.6 TiB.

If your recorder or camera datasheet gives an actual measured bitrate, put it in the override field. A measured figure beats any estimate.

The three decisions that actually move the cost

Retention. Doubling from 30 to 60 days doubles the storage bill. Before you specify it, find out what you are genuinely obliged to keep — often the answer is an insurance clause or a licensing condition, not a technical requirement, and often it is shorter than people assume.

Frame rate. Above 15 fps buys very little for identifying a person or reading a plate, and costs storage in a straight line. 12–15 is the usual sweet spot. Tills, gaming floors and anywhere you need to see hands are the exceptions.

Resolution where it counts. Putting 4K on every camera is the expensive way to get a worse system. Resolution matters at the entrance and the till; a corridor camera at 2 MP is fine, and the saving buys a better camera where it counts.

Add headroom, then add some more

The recommended figure adds 20% over the raw calculation. That covers filesystem overhead, the fact that recorders do not run to 100% full, and the camera somebody adds three months later. If the system is mirrored, double it — RAID 1 is not storage, it is insurance, and it costs you half the array.

Getting this designed properly

Sizing storage is the easy part. Placement, lighting, retention policy and the network the whole thing sits on are what decide whether the footage is usable when you need it. That is security camera installation and network design, and we do both on site across Central Oregon.

Powering all those cameras? The PoE budget calculator works out whether your switch can actually carry them.