Field of view calculator
Pick your sensor and focal length to see the exact horizontal, vertical and diagonal angle of view in degrees - plus what that lens is equivalent to on a full-frame body.
Lens & sensor
Choose a preset, or pick “Custom sensor size…” to type width and height.
Result
Angles of view
Equivalent focal length reproduces the diagonal angle on full frame.
How it works
Angle of view comes from simple trigonometry between the sensor dimension and the focal length. The lens forms an image behind itself; the sensor cuts a slice out of that image circle, and the size of that slice versus the distance to it sets the angle.
Run the formula three times - once with the sensor width, once with its height, and once with the diagonal - to get the three angles. The diagonal is always the largest and is the number quoted on lens spec sheets.
Example
A 50 mm lens on full frame (36 × 24 mm) captures a diagonal of 43.27 mm, so the diagonal angle is 2 · atan(43.27 ÷ 100) = 46.8°. The horizontal angle is 2 · atan(36 ÷ 100) = 39.6° and the vertical is 27.0°. On APS-C Canon the same lens frames like an 80.7 mm lens on full frame.
Why it matters
- Predict how much of a scene fits in the frame before you buy or rent a lens.
- Choose the focal length that frames a subject at a known shooting distance.
- Understand zoom-range specs: “24–70mm” only means something once you know the angle it gives on your sensor.
Related tools
Turn the angle back into a lens choice with the focal length calculator, convert between formats with the equivalent focal length calculator, or check how the angle changes depth of field in the DOF calculator. Crop factor basics live in the crop factor calculator.
Frequently asked questions
What is the field of view of a 50mm lens on full frame?
On a 36 × 24 mm full-frame sensor a 50 mm lens has a diagonal field of view of about 46.8°, a horizontal field of view of 39.6° and a vertical one of 27.0°.
Why does the same lens give a smaller field of view on APS-C?
The sensor is smaller, so it captures a smaller central slice of the lens's image circle. On APS-C Canon (22.3 × 14.9 mm) the 50 mm diagonal drops to about 30.0°, which is why it is described as an 80.7 mm full-frame equivalent.
Is the field of view the same as angle of view?
Yes - the terms are used interchangeably. Both describe the angular extent of the scene a lens and sensor combination captures. Field of view can also be expressed as linear width at a given distance, while angle of view is the degree value this calculator shows.