How do you calculate field of view in machine vision?

Divide the camera sensor width by the lens focal length, then multiply by the working distance. With an 8.8 mm sensor, a 16 mm lens and a 400 mm working distance you get (8.8 / 16) x 400 = 220 mm horizontal FOV.

What is a good field of view for inspection?

A good FOV is the smallest one that fits your largest part plus 10-20% framing margin, because a tight FOV puts more pixels on the part and improves defect resolution. For a 180 mm part, a 220 mm FOV gives sensible margin.

How does focal length change field of view?

FOV is inversely proportional to focal length. Doubling the lens from 16 mm to 32 mm at the same 400 mm working distance halves the horizontal FOV from 220 mm to 110 mm, which is why longer lenses zoom in.

Does working distance affect field of view?

Yes, FOV scales linearly with working distance. Moving the camera from 400 mm to 600 mm with the same 8.8 mm sensor and 16 mm lens widens the FOV from 220 mm to 330 mm.

Horizontal vs vertical field of view?

Both use the same formula but with the matching sensor dimension. This calculator returns horizontal FOV from sensor width; swap in the sensor height to get vertical FOV, which is smaller on standard 4:3 and widescreen sensors.

What is the sensor-to-focal-length ratio used for?

That ratio (here 0.55) is the angular scale factor of your optics. Multiply it by any working distance to get FOV instantly, so it is a handy single number to compare lens options before you commit to mounting.

Machine Vision & Industrial Inspection AI calculator

Camera Field of View Calculator

Field of view (FOV) is the physical width of the scene a machine vision camera actually images at a given working distance. Vision engineers and integrators compute it first when specifying an inspection station, because FOV determines whether the whole part fits in frame and, combined with sensor pixels, sets the resolution available to find defects. Get it wrong and you either clip the part out of frame or waste pixels imaging empty conveyor. This calculator uses the similar-triangles relationship between sensor size, focal length and working distance to return horizontal FOV in millimeters.

What this calculator does

Calculate the horizontal field of view (FOV) of a machine vision camera from sensor width, lens focal length, and working distance, so you can confirm the camera sees the full inspection area at the chosen working distance.
Use it when selecting a lens for a new inspection station and you need to confirm that the chosen sensor and focal length combination produces a field of view that covers the full part width at the planned working distance.
It computes the horizontal field of view in mm from camera sensor width, lens focal length and working distance using the similar-triangles optics relationship.

Formula used

Horizontal FOV = (sensor width / focal length) x working distance
Example: (8.8 mm / 16 mm) x 400 mm = 220 mm FOV

Inputs explained

Camera sensor width:
Lens focal length:
Working distance:

How to use the result

Use it when selecting a lens and mounting height for a fixed-mount inspection camera so the part of interest fully fits the frame with margin.
It is a thin-lens paraxial approximation that ignores lens distortion, magnification at very short working distances, and the difference between the optical node and the front of the lens, so verify the final framing on the bench.

Common questions

How do you calculate field of view in machine vision? Divide the camera sensor width by the lens focal length, then multiply by the working distance. With an 8.8 mm sensor, a 16 mm lens and a 400 mm working distance you get (8.8 / 16) x 400 = 220 mm horizontal FOV.
What is a good field of view for inspection? A good FOV is the smallest one that fits your largest part plus 10-20% framing margin, because a tight FOV puts more pixels on the part and improves defect resolution. For a 180 mm part, a 220 mm FOV gives sensible margin.
How does focal length change field of view? FOV is inversely proportional to focal length. Doubling the lens from 16 mm to 32 mm at the same 400 mm working distance halves the horizontal FOV from 220 mm to 110 mm, which is why longer lenses zoom in.
Does working distance affect field of view? Yes, FOV scales linearly with working distance. Moving the camera from 400 mm to 600 mm with the same 8.8 mm sensor and 16 mm lens widens the FOV from 220 mm to 330 mm.
Horizontal vs vertical field of view? Both use the same formula but with the matching sensor dimension. This calculator returns horizontal FOV from sensor width; swap in the sensor height to get vertical FOV, which is smaller on standard 4:3 and widescreen sensors.

Last reviewed 2026-05-12.