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CCTV Field of View Calculator

Enter the sensor, lens, resolution and distance. See the horizontal and vertical field of view, the scene width and the pixel density at your target, with diagrams drawn from the same result.

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Camera

Format names are nominal. Use the width and height from the camera datasheet when you have them.

The lens focal length, for example 2.8, 4 or 12.

Distance from the camera to the target, measured along the viewing direction.

Mounting (optional)

Enter both to see the side view and where the camera sees the ground. Clear both to hide it.

At 15.0 m the scene is 20.1 m wide and the pixel density is 127 px/m: Recognize.

Horizontal FOV
67.7°
Vertical FOV
41.4°
Scene width at target
20.1 m
Scene height at target
11.3 m
Pixel density at target
127 px/m
Level reached
Recognize
Ground visible from
6.27 m
Ground visible to
no limit
Plan view. The camera has a horizontal field of view of 67.7°. At 15.0 m the scene is 20.1 m wide and the pixel density is 127 px/m, which is Recognize.Scene width20.1 m127 px/mRecognizeHFOV67.7°Target distance 15.0 mMonitor, needs 12.5 px/mDetect, needs 25 px/mObserve, needs 62.5 px/mRecognize, needs 125 px/mIdentify, needs 250 px/mInspect, needs 1000 px/m
Plan view. Drawn from the results above: the wedge ends at the scene width, and the coloured strip along the viewing direction shows the level reached at each distance.
Side view. The camera is 4.50 m high and tilted 15.0° below horizontal, with a vertical field of view of 41.4°. Ground becomes visible 6.27 m from the camera and has no far limit. The target is 15.0 m along the viewing direction.Ground visible from6.27 mNo far ground limitHeight4.50 mTilt15.0°VFOV41.4°Target distance 15.0 m
Side view for the camera height and tilt entered. Ground is the flat floor; the target is a flat surface facing the camera at the target distance.
Levels reached along the viewing direction
LevelNeedsReached up toAt this target
Monitor12.5 px/m153 mMet
Detect25 px/m76.3 mMet
Observe62.5 px/m30.5 mMet
Recognize125 px/m15.3 mMet
Identify250 px/m7.63 mNot met
Inspect1000 px/m1.91 mNot met

How the result is calculated

The calculator uses the same optics functions as the CCTV Design Tool designer, so a camera entered here gives the same numbers as the same camera placed on a plan.

HFOV = 2 x arctan( sensor width / (2 x focal length) )
VFOV = 2 x arctan( active sensor height / (2 x focal length) )
scene width = 2 x distance x tan( HFOV / 2 )
pixel density = horizontal pixels / scene width
  • Changing the resolution changes the pixel density, not the field of view. The aspect ratio can change the vertical field of view, because the active sensor height follows it.
  • The level shown is the highest one whose pixel-density requirement is met at the target distance.
  • With height and tilt entered, the side view shows where the upper and lower edges of the image meet the ground.

Assumptions and limits

  • A pinhole (rectilinear) lens, no distortion. Wide lenses above about 120 degrees are flagged because the model overstates coverage near the edges.
  • The target is a flat surface facing the camera. A tilted camera looking at the ground sees a trapezoid, not a rectangle.
  • Nominal sensor sizes. The datasheet size of the actual camera is more accurate.
  • Pixel density is a geometric planning figure. It does not account for lighting, motion, compression or occlusion, and it does not guarantee that a person can be recognised or identified.
  • Results are planning estimates. Confirm critical positions on site.

Read the full methodology for units, thresholds and standards references.

Calculator version 1.0. Last reviewed 2026-09-21.

What to do next

Understand the geometryThe field of view guide explains sensor size, focal length, height and tilt with a worked example.Choose the level you needHow Detect, Observe, Recognize and Identify relate to pixel density.Continue in CCTV Design ToolPlace this camera on a floor plan and review coverage against walls, height and tilt.
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