Field of View Calculator

What it does

Calculates the actual angle of view your lens and sensor combination captures — how wide a slice of the scene fits in frame — in three directions: horizontal (left-right), vertical (top-bottom), and diagonal (corner-to-corner, the number most often quoted in lens marketing).

What you'll need

• Focal length in mm — the lens's actual focal length, not a 35mm-equivalent.
• Sensor format — determines the physical sensor dimensions the angle is calculated from.

Steps

1. Enter your focal length.
2. Pick your camera's sensor format.
3. Read the horizontal, vertical and diagonal angle of view.

Reading the result

A larger angle means a wider view (more of the scene fits in frame); a smaller angle means a narrower, more zoomed-in view. Diagonal is the figure most commonly quoted for a lens, but horizontal and vertical are usually more useful in practice — horizontal for how much of a wide scene you'll capture, vertical for how much headroom or ceiling you'll get in a tighter shot.

Tips

• Two different focal length + sensor combinations can produce the same field of view — that's exactly what the Crop Factor Calculator translates between.
• For architecture or interiors, vertical angle of view often matters more than horizontal — a lens that's plenty wide horizontally can still clip a ceiling or feel cramped vertically in a tight room.

What is field of view (angle of view)?

Field of view — or angle of view — is the actual angular slice of a scene a lens and sensor combination captures, measured in degrees. It depends on two things together: the lens's focal length, and the physical size of the sensor recording the image. The same focal length produces a different field of view on a full-frame sensor than on a smaller APS-C or Micro Four Thirds sensor, which is exactly what “crop factor” describes.

Why photographers use it

Knowing the actual angle of view — not just a focal length number — lets you predict how much of a scene will fit in frame before you're even on location, which is especially useful when comparing lenses across different cameras or sensor formats where focal length alone doesn't tell the full story.

Common mistakes

• Comparing focal length numbers across different sensor formats. 50mm means something different in terms of actual field of view on full-frame versus APS-C versus Micro Four Thirds. Compare field of view in degrees, or full-frame-equivalent focal length, not raw millimetre numbers across formats.
• Only checking diagonal field of view. diagonal is the number most often quoted, but horizontal and vertical are usually what actually matters for framing a specific shot — check the one that maps to your actual composition concern.
• Forgetting field of view changes with focus distance for macro work. this calculator assumes the lens is focused at a normal, non-macro distance. At very close focus distances, effective field of view narrows further than the simple formula suggests.

Example settings

FAQ

Why does field of view depend on sensor size, not just focal length?

Because the angle of view is defined by how the sensor's physical width and height compare to the focal length — a smaller sensor sees a narrower slice of the same lens's projected image, which is exactly what a crop factor describes.

Which number should I use — horizontal, vertical or diagonal?

Whichever matches what you're actually solving for. Horizontal for how wide a scene fits side to side, vertical for headroom or ceiling clearance, diagonal mainly for comparing marketing specs between lenses.

How is this different from the Crop Factor Calculator?

Crop Factor Calculator converts a focal length between sensor formats to find an equivalent field of view. This tool calculates the actual angle of view in degrees for one specific focal length and sensor combination.