Home Security Camera Coverage Calculator
Calculate the number of cameras needed to cover your property, the coverage area per camera, and total coverage based on camera field of view and placement height.
Formulas Used
Ground Range (Rg):
Rg = √(R² − h²)
where R = camera max range (ft), h = mounting height (ft).
Coverage Area per Camera (Circular Sector):
A = ½ × Rg² × θ
where θ = field of view in radians = FOV° × (π / 180).
Footprint Width at Max Range:
W = 2 × Rg × tan(θ / 2)
Effective Coverage per Camera:
Aeff = A × (1 − Overlap%/100)
Number of Cameras Needed:
N = ⌈ Total Area / Aeff ⌉ (ceiling function)
Total Coverage Provided:
T = N × A
Assumptions & References
- Camera coverage is modelled as a circular sector (pie-slice) projected onto a flat ground plane — a standard approximation used in security planning.
- The ground range is derived from the camera's line-of-sight range and mounting height using the Pythagorean theorem, assuming the camera is angled to capture the farthest point at ground level.
- Typical residential cameras have a FOV of 90°–120° and a useful range of 20–50 ft for clear identification.
- A 20% overlap is recommended as a minimum to eliminate blind spots between adjacent cameras (ASIS International, Physical Security Standard).
- Mounting height of 8–10 ft is recommended for optimal angle and tamper resistance (per CCTV installation best practices).
- This calculator assumes cameras are optimally placed; real-world obstacles (walls, trees, furniture) will reduce effective coverage.
- For perimeter coverage, consider cameras with wider FOV (110°–130°); for entry-point identification, narrower FOV (60°–90°) at closer range is preferred.
- Reference: IEC 62676-4 (Video surveillance systems for use in security applications) and ASIS International Physical Security Standards.