Field of View Calculator

How to use

1. 1Choose Scene coverage at a distance, pick your camera sensor, and set the unit to metres or feet.
2. 2Enter the lens focal length and how far away the subject is to read the captured width, height, diagonal, area, and angle of view.
3. 3Switch to Fit a subject in frame when you want the inverse: choose whether to solve for the distance to stand or the focal length to use.
4. 4Pick whether the subject should fill the frame vertically or horizontally and enter its real size, for example 1.8 m for a standing person.
5. 5Read the required distance or focal length, check the resulting coverage to leave some margin, and copy the summary for your shot notes.

About this tool

Field of View Calculator works out what a lens actually captures in the real world, which is the question photographers, videographers, and camera planners ask when they need to know how far to stand or which lens to reach for. It answers two related jobs that a focal length on its own cannot. The first is scene coverage: given a camera sensor, a real focal length, and the distance to the subject, it returns the width and height of the scene that fills the frame at that distance, along with the captured diagonal, the covered area, and the angle of view across the horizontal, the vertical, and the diagonal. The geometry is the rectilinear pinhole model. The angle of view for one sensor dimension d and focal length f is two times the arctangent of d divided by twice f, and the captured scene size follows from similar triangles as the sensor size multiplied by the distance over the focal length, so the captured width is the distance times the sensor width divided by the focal length. Because the relationship is linear in distance, doubling how far away you stand doubles the width and height the frame covers, which is why the same 50 mm lens that frames a head and shoulders at three metres frames a whole group from six. The second job is the framing solver, the inverse calculation. Enter the real size of the subject you want to fill the frame, a standing person is about 1.8 metres tall, and choose what to fill: the height or the width. The tool then solves for either the distance to stand at for a focal length you already have, using distance equals the target size times the focal length divided by the sensor dimension, or the focal length to fit the subject from a distance you are fixed at, using focal length equals the distance times the sensor dimension divided by the target size. It reports the resulting captured width and height so you can see how much room is left around the subject and leave headroom. Sensor presets cover medium format, full frame, both common APS-C sizes, Micro Four Thirds, one inch, Super 35 and Super 16 cinema sizes, a typical phone and action camera sensor, and a common security camera sensor, and a custom option accepts any width and height in millimetres for cinema or unusual formats. A reference table lists each sensor size and its crop factor, since a smaller sensor sees a narrower scene from the same lens. This is the practical companion to the crop factor calculator, which converts a lens to its full-frame equivalent focal length and reports the angle of view, and to the depth of field calculator, which gives the sharp zone rather than the coverage. The model is ideal, so very wide lenses with strong distortion are approximate near the edges, and the small focus extension that matters in macro work is left out because it is negligible at normal distances. Every figure is computed in your browser with plain trigonometry. The camera, lens, distance, and subject values you enter never leave your device.

Free to use. Works in your browser. No signup, no login.