Camera Field of View Calculator
The field of view is how much of a scene a lens takes in, set by the focal length and the size of the sensor behind it. A short focal length on a big sensor sees a wide angle; a long lens on a small sensor sees a narrow one. This calculator uses the standard thin-lens geometry to return the angle of view in degrees from your sensor dimension and focal length, and the actual width of scene captured at a chosen subject distance. Enter the sensor width for horizontal results or the height for vertical.
Field of view formula
Angle of view = 2 * atan( sensor / (2 * focal) ) [radians, then to degrees]
degrees = radians * 180 / pi
Scene width = distance * (sensor / focal)
Use sensor width for horizontal, height for vertical
This is the thin-lens approximation focused near infinity. At close focus the effective angle narrows slightly, but the formula is accurate for normal shooting distances.
Field of view context
- Full-frame sensors are 36 by 24 mm; APS-C and Micro Four Thirds are smaller.
- A smaller sensor narrows the angle of view for the same focal length.
- Doubling the focal length roughly halves both the angle and the captured width.
- Captured width grows in direct proportion to subject distance.
- Enter the matching sensor dimension for horizontal, vertical, or diagonal results.
Field of view: frequently asked questions
How is angle of view calculated from focal length?
Angle of view equals 2 times the arctangent of the sensor dimension divided by twice the focal length: AOV = 2 times atan(d / (2 times f)). Use the sensor width for horizontal angle, height for vertical, and the diagonal for diagonal angle. A 50 mm lens on a 36 mm wide full-frame sensor gives about a 39.6 degree horizontal angle.
How wide a scene does my lens capture at a given distance?
Captured width equals the subject distance times the sensor width divided by the focal length: width = distance times (sensor width / focal length). At 10 metres a 50 mm lens on a 36 mm sensor captures about 7.2 metres across. The same ratio applies to height with the sensor height.
What sensor dimensions should I use?
Full-frame is 36 by 24 mm. APS-C is roughly 23.5 by 15.6 mm (Sony, Nikon, Fujifilm) or 22.3 by 14.9 mm (Canon). Micro Four Thirds is 17.3 by 13 mm. Because exact dimensions vary slightly by manufacturer, this calculator takes the sensor width and height as inputs.
Does the crop factor change the angle of view?
A smaller sensor crops the image circle, so it captures a narrower angle for the same focal length. That is why a 50 mm lens looks like a longer lens on APS-C. Entering the actual sensor dimensions handles this automatically: no separate crop factor is needed.
Is this the diagonal or horizontal field of view?
This calculator reports the angle of view for whichever sensor dimension you enter. Horizontal uses the sensor width, vertical uses the height. The captured width at distance uses the same dimension, so keep the sensor figure consistent with the angle you want.
Official sources
- NIST: optical metrology and SI length units.
- CIPA: Camera and Imaging Products Association standards.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.