Calculate horizontal, vertical, and diagonal angle of view, required focal length, or scene coverage from sensor format, lens focal length, and distance.

Rectilinear distant-focus model. Distortion and focus breathing are not modeled; close-focus coverage may differ substantially.

Angle of View Formula

The calculator uses one core trigonometric relationship and rearranges it for each mode.

AOV = 2 × arctan(d / (2 × f))

Frame size mode:

Frame = D × d / f

Focal length mode:

f = d / (2 × tan(AOV / 2))
  • AOV = angle of view in degrees (horizontal, vertical, or diagonal)
  • d = sensor dimension (width, height, or diagonal) in mm
  • f = lens focal length in mm
  • D = subject distance in mm
  • Frame = the width, height, or diagonal of the scene captured at distance D

Assumptions: the formula treats the lens as a thin lens focused at infinity, ignores distortion, and assumes the subject distance is much larger than the focal length. At close-focus distances, image distance and focus breathing can change coverage substantially; the direction and magnitude depend on the lens. This calculator does not model those effects. The 35mm-equivalent focal length shown in results scales by the ratio of the full-frame diagonal (43.27 mm) to your sensor diagonal.

Reference Tables

Diagonal angle of view for common focal lengths on popular sensor formats:

Focal length Full-frame APS-C (23.6 × 15.7 mm) MFT 1-inch
14 mm114°91°75°59°
24 mm84°61°49°37°
35 mm63°44°34°26°
50 mm47°32°24°18°
85 mm29°19°15°11°
200 mm12°8°6°5°

How a diagonal angle translates to lens character on a full-frame body:

Diagonal AOV Lens type Typical use
Above 90°Ultra-wideInteriors, real estate, astro
63° to 84°WideLandscape, environmental
40° to 63°NormalDocumentary, street, video
18° to 40°Short telephotoPortraits, products
8° to 18°TelephotoSports, wildlife
Below 8°Super-telephotoDistant wildlife, surveillance

Worked Example

A 50 mm lens on a full-frame sensor (36 × 24 mm, diagonal 43.27 mm):

  • Horizontal: 2 × arctan(36 / 100) = 39.6°
  • Vertical: 2 × arctan(24 / 100) = 27.0°
  • Diagonal: 2 × arctan(43.27 / 100) = 46.8°

At a distance of 3 m from the subject, the frame covers 3 × 36 / 50 = 2.16 m wide by 1.44 m tall. To fit a 2 m wide subject from that same 3 m distance, you need 36 × 3000 / 2000 = 54 mm.

FAQ

Why are three angles reported? Lens specs usually quote the diagonal value because it is the largest, but the horizontal and vertical angles tell you what fits left-to-right and top-to-bottom. Use diagonal for comparing lenses, horizontal or vertical for framing real subjects.

Does the angle change when I focus closer? It can. Focus breathing and the lens design can change angle of view, especially at close focus. Check lens-specific data; this distant-focus model does not predict that change.

How does crop factor relate to this? Crop factor is the ratio of the full-frame diagonal to your sensor diagonal. Multiplying your focal length by the diagonal crop factor gives the full-frame focal length with the same diagonal angle of view; horizontal and vertical framing also match only when aspect ratios match, which is the "35mm equivalent" shown in the results.

Angle of View Calculator screenshot
angle of view formula