Translate entrances, indoor spaces and outdoor zones into camera views.
How this calculator works
Security design starts with the views that matter: entrances, circulation areas, gates, parking and critical rooms. The calculator builds a zone-based camera count, then sizes the recorder, storage, PoE switching and UPS.
Round upward to an NVR channel tier with spare capacity.
Estimate retention storage from resolution, bitrate, recording mode and overhead.
Worked example
A practical planning scenario
A duplex with two entrances, a gate, parking and several indoor circulation areas may need twelve cameras even when the building area alone suggests fewer. That normally maps to a 16-channel NVR with room for future views.
Frequently asked questions
How many cameras does a house need?+
There is no universal number. Entrances, gates, parking, blind spots, property shape and the identification detail you need all matter.
Is 4 MP enough?+
4 MP is a useful general-purpose tier for many views. Gates, tills or other identification-critical zones may need different lenses, placement or resolution.
Why leave empty NVR channels?+
Practical headroom makes it easier to add a camera later and avoids choosing hardware that is already at its limit.