Field of View Calculator

Calculate horizontal, vertical and diagonal field of view from sensor size and focal length. Live results with camera presets.

Inputs

Camera / sensor

Focal length (mm)

Press Calculate to update results.

Results

What is field of view?

Field of view (FOV) is the angular width of the scene projected onto the sensor. It depends on focal length and the active sensor dimensions. A 24 mm lens on full frame sees a wide landscape; the same 24 mm lens on Micro Four Thirds sees a much narrower slice—closer to a 48 mm full-frame view.

Photographers use FOV to plan coverage: how much of a room a lens will show, whether a wildlife subject fills the frame, or how a cinema lens will read on different sensor modes. This calculator reports horizontal, vertical and diagonal angles using the standard arctangent formula.

Formula

FOV = 2 × arctan( sensor_dimension / (2 × focal_length) )

Use sensor width for horizontal FOV, height for vertical, and the diagonal for the corner-to-corner angle.

Example

Full-frame (36 mm wide), 35 mm lens → horizontal FOV ≈ 54°. On a 1.5× APS-C sensor the same lens yields about 38° horizontal—similar to a 52 mm lens on full frame.

FAQ

Does aperture change FOV?

Not in normal use. Some lenses exhibit focus breathing, which slightly changes focal length (and thus FOV) as you focus.

Is FOV the same as magnification?

No. FOV is an angle. Magnification describes image size on the sensor relative to subject size, critical in macro work.

Planning coverage with FOV

Before a real-estate or architecture job, estimate room widths and standing distance, then check whether a 16 mm, 24 mm or 35 mm lens on your body covers the space without extreme stretch. Wildlife and sports shooters do the opposite: start from subject size and distance, solve for the focal length that fills the frame, then confirm FOV so crop mode or a teleconverter does not surprise you.

Matching FOV across full-frame and crop bodies keeps multi-cam angles consistent. Enter each sensor preset with the focal length mounted and compare horizontal angles until they align. That matters for documentary kits where one operator runs APS-C and another runs full frame on the same story.