Camera Count for Area Calculator

Estimates how many cameras a site needs to cover its perimeter, from the site size, the lens field of view, coverage distance and an overlap allowance. It runs entirely in your browser and shows the working, so you can check every step against your own figures.

How the camera count for area calculator works

Each camera covers a run of perimeter equal to its coverage width, reduced by the overlap you want between neighbours so there are no gaps. The site perimeter is twice the length plus the width. Dividing the perimeter by the per-camera run and rounding up gives the number of cameras for continuous perimeter cover.

What you enter

Enter the site dimensions, lens angle, coverage distance and overlap; the calculator returns the number of cameras for perimeter cover. Every field is editable, and the result recalculates the moment you change a value.

Reading the result

This is a floor, not a full plan — add cameras for entrances, blind corners and any internal areas the perimeter ring does not see. Overlap avoids gaps where a person could slip between two views.

Safe by design

This tool plans coverage, storage and cable length. It never specifies conductor gauge or PoE circuit sizing — the electrical side is a qualified installer’s responsibility.

Assumptions and limits

This covers a rectangular perimeter with identical cameras. Real sites have obstructions, corners and entry points that need dedicated cameras, and a mix of wide and narrow lenses. Treat the number as a starting estimate for a proper survey.

Using it with the rest of BuildMetricLab

This calculator is one step in planning the job. Pair it with the related tools in this category and across BuildMetricLab to go from a single figure to a full costed plan — a sizing figure feeds a cost estimate, a cost estimate feeds a project budget, and each result carries straight into the next tool. Every BuildMetricLab tool runs entirely in your browser — no sign-up, nothing sent to a server, and the formula is shown on the page so the maths can be audited.