Security Camera Coverage Calculator

How to use this calculator

Pick your property type, which sets a baseline number of zones a property that size usually needs covered. Enter how many cameras you plan to run, then pick the lens field of view. Check the zones that matter most to you. The tool compares your camera count and lens against the zones to cover, then reports a coverage percentage, a recommended camera count, and an estimate of how many priority zones are still blind.

How the coverage math works

• Zones to cover: Each property type sets a baseline demand: a small lot needs about 3 zones, a suburban home about 4, a large lot 5, and a multi-building property 6 or more. The tool uses the larger of that baseline or the number of zones you checked.
• Coverage per camera: A wide-angle 110 degree lens covers about 1.2 zones per camera, a standard 90 degree lens about 1.0, and a telephoto 60 degree lens about 0.6 because its narrow cone leaves gaps between cameras.
• Coverage percentage: Camera count times coverage per camera, divided by the zones to cover, capped at 100 percent.
• Recommended count: The zones to cover divided by the coverage per camera, rounded up. Telephoto setups need more cameras for the same property.
• Blind spots: The priority zones your current camera count and lens cannot reach. This is a planning heuristic, not a 2D geometry model, so confirm it by walking the property after install.

Pro tips for camera coverage

1. Cover the entry-point hierarchy first

About 80 percent of break-ins come through the front door, a ground-floor window, or the garage side door. Cover those first regardless of property size, then move outward to the driveway, back yard, and fence lines.

2. Pair cameras with lighting

A camera in the dark just records dark footage. Color night vision needs ambient light or an integrated spotlight. Plan the lighting alongside the cameras with the Outdoor Security Lighting Spacing Calculator.

3. Two-way audio at the property line

Recording sound can carry stricter rules than recording video. In Canada, PIPEDA covers commercial use, and the Office of the Privacy Commissioner guidance says residential cameras should face your own property. In the United States, twelve jurisdictions are two-party-consent for audio: California, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, Nevada, New Hampshire, Pennsylvania, Washington, plus the District of Columbia. Disable two-way audio when a camera faces beyond your property line.

4. Cloud vs local storage tradeoff

Cloud storage runs about 3 to 20 USD or 5 to 30 CAD per camera per month and survives camera theft, but it needs working internet. A local network video recorder (NVR) is a one-time 300 to 600 USD or 400 to 800 CAD with no monthly fee, but the footage is at risk if the recorder is stolen. Hybrid, meaning local recording with cloud backup on motion events, is the modern recommendation.

5. Canadian privacy law context

PIPEDA covers commercial use, while personal and residential recording is governed by provincial Privacy Acts: British Columbia and Alberta have their own Privacy and Personal Information Protection Acts, and Quebec runs the strict Law 25 (Bill 64). Office of the Privacy Commissioner guidance is that residential cameras should face your own property, and signage is recommended if you record audio. In the United States, CCPA-style laws in California, Virginia, Colorado, Connecticut, and Utah extend similar protections.

What to check before you buy

• Match lens to distance. Use wide-angle for entry points and short driveways, telephoto only for a long approach where you need plate-level detail.
• Confirm the recommended count. If the tool recommends more cameras than you planned, prioritize the entry-point zones first and add the rest in a second phase.
• Plan power and cable runs. Wired and power-over-ethernet cameras are the most reliable. Map the runs before you drill.
• Set the storage plan. Decide cloud, local, or hybrid before you buy, because it changes the monthly cost and the recorder hardware.
• Walk the property after install. The blind-spot estimate is a planning heuristic. Confirm real coverage on the live footage at night.

Common mistakes

• Over-watching one zone. Three cameras on the front door and nothing on the back leaves the most common second entry point blind.
• Telephoto everywhere. Narrow lenses look impressive on a spec sheet but leave wide gaps between cones. Use them only for the long approach.
• Forgetting the garage side door. It is one of the top three entry points and one of the most overlooked.
• Cameras without lighting. A dark scene records as dark footage. Lighting and cameras are one project, not two.
• Audio at the fence line. Two-way audio aimed at a neighbor can break two-party-consent rules. Turn it off at the property line.

FAQ

How many security cameras does a typical house need?

Most homes are well covered by 4 to 6 cameras: the front door, the driveway or front approach, the back door or back yard, and the garage side entry. Small townhouse lots are usually fine with 2 to 3 wide-angle cameras on entry points. Large lots and acreage with outbuildings can need 6 or more. This calculator gives a recommended count from your property type, the camera field of view, and the zones you mark as priorities.

What field of view should a security camera have?

A wide-angle lens around 110 degrees is the best all-rounder for entry points and short driveways because one camera covers more of the scene. A standard 90 degree lens is the common consumer balance. A telephoto 60 degree lens is for long approaches and license-plate detail, but its narrow cone leaves blind spots between cameras, so you need more of them to cover the same property.

What causes blind spots with security cameras?

Blind spots come from too few cameras for the number of priority zones, narrow field-of-view lenses with gaps between their cones, mounting too low so the camera sees a small patch, and aiming at the sun so backlight blacks out the frame. The calculator estimates blind spots as the priority zones your current camera count and lens cannot reach.

Is it legal to point a security camera at my neighbor's property?

Aim cameras at your own property. In Canada, the Office of the Privacy Commissioner guidance for residential cameras is that they should capture your own property, and signage is recommended if you record audio. Provincial Privacy Acts in British Columbia, Alberta, and Quebec (Law 25) add stricter rules. In the United States, twelve jurisdictions are two-party-consent for audio, so disable two-way audio when a camera faces beyond your property line. When in doubt, angle the camera down and inward and turn audio off at the fence.

Should I choose cloud or local storage?

Cloud storage runs about 3 to 20 USD or 5 to 30 CAD per camera per month and survives camera theft, but needs a working internet connection. A local NVR is a one-time 300 to 600 USD or 400 to 800 CAD with no monthly fee, but the footage is at risk if the recorder itself is stolen. The modern recommendation is hybrid: local continuous recording with cloud backup on motion events.