CCTV Field of View Calculator

Welcome to our CCTV Field of View Calculator page. We hope you find it a helpful tool for being able to choose the correct lens for your security camera. Please contact us if you need any help or have any questions.

Trying to determine the correct lens for your camera is one of the most important parts of making sure you will have an effective video security system. The wrong lens can mean you are either going to miss details that you want to capture. Either from the lens focal view being to far away from the scene or perhaps even being too close to the scene.

It all comes down to your Field of View.

What is Field of View? It is simply what is the width and the height (in feet and inches) of what your camera and lens are going to capture.

I provide details that explain how this works specifically for security cameras at the following link.

What is Field of View for CCTV Security Camera Systems?

Once you have a good understanding of it then the calculator below will become a valuable tool in helping dial in your video security system and achieve the safety and security you are after.


  1. Select the lens format you are using.

  2. Enter any 2 of the 3 other pieces of information.

  3. Press the "Calculate" button to get the missing piece of information. (Press the "Reset" button to clear the form and start over.)

Select lens format: 
1/4 inch
1/3 inch
1/2 inch
2/3 inch
1 inch

Enter distance to object (in feet): 1


Enter width of scene (in feet):  2

Enter height of scene (in feet): 2

Enter size of lens (in millimeters): 3

Do you need a more powerful CCTV Design Tool?

Save time trying to figure out how to find optimal positions for your CCTV cameras and calculating field of view, viewing angles and lens focal lengths. Use the CCTV Design Tool. It is for anyone who wants to design a perfect CCTV system. Try the free trial version now.

Here are some of the key features

  • Be able to save your work
  • Graphically show camera views and placement
  • Easily calculate field of view and focal lengths
  • Can be switched between metric or standard measurements
  • Set up multiple cameras
  • Include actual installation height as part of the overall view
  • Copy and Paste drawings into your word processor to share with your installers or customer
  • 3D viewing to give a clear view of what you will see with the cameras

Click Here to See the various options and download the one that is right for you.

Learn more about CCTV Field of View

What is field of view and why is it important? Field of view is all about what someone will be able to see through the security camera. We will define it in detail and explain how it works and provide some examples to make it easier to understand. Feel free to use the CCTV Field of View Calculator above for your own calculations.

The field of view (or FOV) is the total height and width of the view seen through the cctv security camera lens. It can also be referred to as the angle of view or the angular field of view. The angular field of view is stated in horizontal and vertical degrees. The question is degrees of what? Well its degrees of a circle. If you look at the picture of the circle you will see that the dark blue section could be stated as 43.6 degrees field of view or angle of view. The full circle is 360 degrees.

So specifically when we are talking about CCTV field of view for security cameras we are looking for a linear field of view. Meaning we are looking for the actual measurement in feet and inches. The Horizontal FOV (Field of View) is the width of the view. The Vertical FOV (Field of View) is the height of the view. The overall FOV is a combination of the horizontal FOV and the vertical FOV. You can even measure it diagonally if you want too but its really not necessary to do that.

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