Camera Field of View Calculator
Calculate the ideal rectangular camera field from sensor dimensions and effective focal length.
Calculate locally
No account, API or uploaded inputs. All calculations run in this browser.
Worked example
A 20 × 10 mm sensor at 100 mm focal length gives horizontal field 11.421186°, vertical field 5.724810° and diagonal field approximately 12.758740°. Swapping width and height swaps horizontal and vertical fields.
Method and units
For each sensor dimension s, field = 2 atan(s/(2f)), converted from radians to degrees. For the diagonal use s = √(width² + height²). All lengths use millimetres. This uses rectilinear pinhole geometry rather than the small-angle shortcut.
What this result means
Enter the active sensor or crop dimensions and effective focal length, not a full-frame equivalent. Distortion, vignetting, image-circle limits and optical aberrations are omitted. This does not model fisheye projection. Rotation changes the orientation on the sky, not these angular dimensions.