Field of View Calculator

Angle of view is how wide a scene a lens takes in, measured as an angle in degrees. This tool computes it as 2 times the arctangent of the sensor dimension divided by twice the focal length, using the rectilinear thin-lens model focused at infinity.

Each uses a different sensor dimension. The sensor width gives the horizontal angle, the height gives the vertical angle, and the corner-to-corner diagonal gives the largest figure, which is the number lens makers most often quote.

Coverage width equals the subject distance times the sensor width divided by the focal length, which is the same as 2 times distance times the tangent of half the angle. The identical formula with sensor height gives the coverage height. Leave the distance blank and the coverage cards show a dash.

Yes, strongly. A smaller sensor captures a narrower angle for the same focal length, which is why a 50 mm lens looks much tighter on APS-C than on full frame. Use the sensor presets to see the effect instantly.

Four buttons set common sizes: Full frame at 36 x 24 mm, APS-C at 23.5 x 15.6 mm, Micro 4/3 at 17.3 x 13 mm and 1 inch at 13.2 x 8.8 mm. You can always overwrite the width and height with your own exact sensor dimensions.

Yes. The width and height fields are independent, so you can model any aspect ratio, a cropped video mode, or a large-format sensor. The angles and coverage update from whatever numbers you enter.

This uses an idealised rectilinear thin-lens model that assumes focus at infinity. Real lenses focus closer than infinity, breathe as you focus, and add distortion, so very wide, fisheye or macro setups can read a little differently from the calculated angle.

Focal length and sensor dimensions are in millimetres, subject distance is in metres, and coverage is returned in metres. Angles are in degrees. Keep distances in metres for the coverage figures to make sense.

Yes. Every calculation runs locally in your browser with no upload. The tool does not read your photos or camera; it only uses the numbers you type, and nothing is stored or sent anywhere.