Free tool
CCTV Pixel Density Calculator
Check whether a camera gives enough pixels per metre to detect, recognise or identify a person at a given distance, using the EN 62676 standard.
The number that decides whether footage is evidence
Pixel density is how many horizontal pixels fall across one metre of the scene. It is the honest measure of a camera system, because megapixels mean nothing until you know how wide a view those pixels are spread across. A 4K camera watching a car park can easily deliver worse detail than a 2 MP camera watching a doorway.
The EN 62676 standard sets the thresholds. Around 25 px/m is enough to monitor movement, 62 px/m to detect that a person is there, 125 px/m to recognise someone you already know, and 250 px/m to identify a stranger from the footage alone. Below 125 px/m, nobody will be identified from your recording no matter how expensive the camera was.
This is why cameras get specified per task rather than per room. One wide camera for the overview, one tight camera on each entrance at identification density. Anyone promising both from a single camera is selling you the overview and calling it evidence.