How to Use the Lens FOV Calculator
Select your camera's sensor size and enter the lens focal length to instantly calculate the crop factor, 35mm equivalent focal length, and horizontal, vertical, and diagonal field of view angles. This helps you understand exactly what angle of view a lens will give on a specific camera body, or compare lenses across different systems.
The FOV formula is: FOV = 2 × arctan(sensor dimension ÷ (2 × focal length)). Crop factor = 43.27mm (full-frame diagonal) ÷ sensor diagonal. A 50mm lens on an APS-C Sony camera (1.5× crop) gives a 75mm equivalent field of view — narrower than a standard lens perspective.
Frequently Asked Questions
Yes. A larger crop factor means a narrower (more telephoto) field of view for any given focal length. A 200mm lens on a 2× crop MFT camera gives the same angle of view as a 400mm lens on full frame.
Yes. Select "1/2.3-inch" for a typical smartphone sensor or use "Custom size" to enter the exact sensor dimensions from the phone's specs.
A diagonal FOV of about 40–50° corresponds to a "normal" perspective similar to human vision — roughly 43mm on full frame or 28mm on APS-C.