Field of View Calculator

Pick your sensor and focal length — get the horizontal, vertical and diagonal angle of view, plus the real scene width and height at any distance you choose.

Free Instant No sign-up

Your camera & lens

Sensor
Units
Horizontal field of view
0°
0vertical
0diagonal
0scene width
0scene height
Quick combos

What lens do I need?

To frame a subject of a given width at a distance, with the current sensor.

Focal needed: — mm

How field of view is calculated

The angle of view depends on the sensor size and the focal length:

Angle=2 × arctan( sensor dimension ÷ (2 × focal) )

We apply that formula to the sensor's width, height and diagonal to give all three angles. Shorter focal length means wider; a bigger sensor too. The angles are at infinity focus, as makers publish them. For the scene width and height at the subject distance we use the thin lens: width = sensor width × (distance − focal) ÷ focal. Far away it matches distance × sensor ÷ focal; up close it does not: a 200 mm on full frame at 1 m frames 14.4 cm wide, not 18. "What lens do I need?" runs the same formula backwards: focal = distance × sensor ÷ (width + sensor).

Example: the field of view of a 50 mm on full frame

A 50 mm on full frame (36 × 24 mm sensor):

  • Horizontal = 2 × arctan(36 ÷ 100) ≈ 39.6°.
  • Vertical ≈ 27.0°; diagonal ≈ 46.8°.
  • At 10 m, the scene covers ≈ 7.16 × 4.78 m.

The same 50 mm on APS-C (1.53×) narrows to 26.4° horizontal: it frames like a mild telephoto.

Field of view FAQ

What is field of view?
It is the angle of scene your lens covers, in degrees. It depends on focal length and sensor size: shorter focal length and bigger sensor mean a wider angle.
How is the angle of view calculated?
With the formula 2 × arctan(sensor dimension ÷ (2 × focal length)). It is computed separately for horizontal, vertical and diagonal using each sensor dimension, with the lens focused at infinity, which is how makers publish it.
How much does my frame cover at a given distance?
With the thin-lens model: scene width = sensor width × (distance − focal) ÷ focal, all in mm and with the distance measured from the lens. The calculator gives the width and height at the distance you set (in cm below 1 m, in inches below 1 ft).
Why does the same lens "see" differently on APS-C?
Because the smaller sensor crops the edges, narrowing the angle of view. A 50 mm gives 39.6° on full frame but 26.4° on APS-C (1.53×).
Which focal length for a portrait or a landscape?
Portrait: 85-135 mm (narrow angle, flattering compression). Landscape and architecture: 14-35 mm (wide angle). Try the combos in the tool.