How Many Security Cameras Do I Need?

The wrong way to count

Camera kits are sold in twos, fours and fives, so people work backwards from the box. That is how you end up with a camera pointed at a fence nobody has ever climbed, and no camera on the side door a delivery driver uses twice a day. The number of cameras you need has nothing to do with the size of your house or the size of a kit. It is the number of ways in that you cannot already see.

This guide is a method, not a product list, though it ends with the cameras we would buy for each kind of spot. It does not claim any camera prevents crime — that is not something a spec sheet can tell you, and we are not going to invent a statistic for it. What a camera does reliably is record who came to a particular place, which is why the count starts with places.

Step 1: List the ways in

Walk around the outside of your home once and write down every door, every ground-floor window a person could fit through, the garage door, and any gate that leads to the back. Include the route a stranger would take from the street to each of them. For a typical detached house that is a front door, a back door, maybe a side or garage door, a driveway and a rear yard. For a townhouse it is often just front and back. For an apartment it is one door.

Step 2: Cross off the ones you can see

A camera is a substitute for a window you are not looking out of. If the front door is visible from the room you spend evenings in, a video doorbell — which you probably want anyway, for deliveries — covers it; our video doorbell ranking is that decision. If the back door opens onto a fenced yard nobody can enter without passing the side gate, the side gate is the spot, not the door. What remains after crossing off is your real count, and for most homes it is two to four.

Step 3: Match each spot to a camera type

Now the count meets the hardware. Two questions per spot decide the camera. Is there power? A spot near an outlet or a drillable wall can take a plug-in camera, which records continuously and never needs charging; a fence post or a shed cannot, and takes a battery camera. Our wired vs wireless guide is the long version. How wide is the view? Every maker publishes a field of view, and it tells you how many spots one camera can merge.

Two things to read into that table. A wider lens merges spots — a 143-degree camera at a rear corner can see both the back door and the side gate — but everything in it is smaller, so a wide camera works best closer to the door. And a pan-tilt camera is a different tool: the Reolink’s lens is no wider than Ring’s, but it swings through 355 degrees, so one mount on a back wall can cover a yard that would otherwise take two fixed cameras. Battery cameras also have a detection range that has nothing to do with the lens — Reolink publishes 33 feet for the Argus PT Ultra’s PIR sensor — beyond which the camera simply does not wake up.

Step 4: Put them at the right height

Ring’s positioning guidance is the clearest any brand publishes and it applies to all of them: outdoor cameras “mounted 8 to 10 feet from the ground with a 20-degree tilt,” doorbells at 48 inches, indoor cameras up to 8 feet. Too high and you record the tops of heads; too low and the camera is easy to reach. And never through a window if you can avoid it — Ring says facing a window “can cause issues with motion detection and video quality,” and battery cameras cannot detect motion through glass at all. Our placement guide covers height, light and the legal lines around neighbors in detail.

Worked examples

A two-bedroom apartment. One way in. A video doorbell or a plug-in camera inside the door, and you are done. Our apartment security page covers the rest of that setup.

A townhouse with front and back doors. Two. A doorbell at the front; a plug-in camera under the rear eave if there is power, a battery camera if not.

A detached house with a driveway, a side gate and a back yard. Three to four. Doorbell at the front, a camera covering the driveway and garage, a camera on the side gate, and either a fixed camera or a pan-tilt camera for the back. This is the one case where a four-camera kit is the right shape rather than a leftover.

The cameras we would buy for each kind of spot

With the count done, the shopping is short. For a house whose count is four, the eufyCam S330 kit is four cameras, solar power and a HomeBase that stores everything with no fee — eufy publishes 16GB built in and expansion to 16TB. For a count of two or three on a tight budget, the Blink Outdoor 4 kit publishes two years on AA batteries and is often the cheapest multi-camera kit, with the storage caveat our Blink review spells out. For one awkward yard, the Reolink Argus PT Ultra pans 355 degrees and records 4K to a card. And for any single spot near power, the Tapo C120 records continuously for the price of a takeout dinner.

Why more is not safer

Every camera is a device with a battery to charge, firmware to update, a password to protect and footage to check. A battery camera you stopped charging in March is a decoration. A cloud camera on a lapsed plan records nothing. Eight cameras produce eight streams of alerts, and the usual outcome is that notifications get muted for all of them. The FTC’s guidance on home cameras is mostly about the account behind them — unique passwords, two-factor authentication, keeping software current — and every extra camera is another account to keep that way. Two well-placed cameras you actually maintain are worth more than a box of five you do not. If your count is small, be pleased about it, buy the best camera for each spot, and spend what you saved on the night-vision specs that matter at the one door that counts.