CCTV calculators

The sums every camera plan needs — how far a camera identifies, how many pixels land on a face, which lens covers a doorway, how many disks the recorder wants — worked out in the browser with the same optics the editor uses.

DORI distance calculator

How far a camera can detect, observe, recognise and identify a person, from its resolution and lens.

Pixel density calculator

Pixels per metre at a distance, the DORI tier it meets, and how many pixels land on a face or a plate.

Lens and field-of-view calculator

Angle of view and scene size from a focal length and sensor, or the focal length a scene needs.

CCTV storage calculator

Bit rate and disk space for a system, from cameras, resolution, codec, frame rate and retention.

Camera finder

Pick what the camera must do and at what distance; the database ranks the models that can.

Why the numbers match the plan

These calculators share their maths with the camera database and with the CameraCAD editor: the same DORI densities from EN 62676-4, the same pinhole and fisheye projections, the same sensor tables. A distance you work out here is the ring the editor draws when you place that camera on a floor plan, and the model pages in the database list it for every camera at both ends of its lens.

What a calculator cannot see is the room. Walls, shelving and mounting height decide what a camera actually covers; the editor ray-casts every cone against the plan so the blind spots show before the install.