Security System Calculator

Total Cameras is built from exactly three inputs -- Building Perimeter (one camera per 40 ft), Interior Area (one camera per 2,500 sq ft), and Entry/Exit Points (one camera per point) -- and Building Perimeter has the largest measured effect on it at this calculator's defaults, both because it produces the most cameras of the three at the default values and because its declared range (10 to 50,000 ft) allows a far bigger swing than the other two. Controlled Doors, Camera Resolution, and Recording Retention never affect Total Cameras at all -- they're not just small contributors, they're structurally absent from the camera-count formula entirely. Controlled Doors instead drives Card Readers and Door Controllers; Camera Resolution and Recording Retention instead drive Storage Needed, since higher resolution means more bits per second recorded and longer retention means more days of footage kept.

Storage scales as the product of camera count, per-camera bitrate (which roughly doubles from 2MP to 4MP and doubles again to 8MP -- a 4x jump from 2MP straight to 8MP/4K), and retention days, so a facility that doubles its camera count AND upgrades from 2MP all the way to 4K AND doubles its retention period sees storage requirements multiply by roughly 16x (2x camera count x 4x resolution x 2x retention), not 2x. Ten percent of the camera fleet is assumed to be PTZ units drawing more PoE power per camera than fixed cameras, which is reflected in the PoE power budget and switch-count outputs but has no bearing on the camera count itself.