What Is a Camera Field of View Calculator?
Field of view is the angular extent of a scene captured by your camera and lens, measured in degrees. It depends on two things: the lens's focal length and the physical size of the camera's sensor. This calculator computes horizontal, vertical and diagonal field of view from those two inputs, using the same trigonometry lens manufacturers use to publish angle-of-view specifications.
This is especially useful for comparing how "wide" or "tight" the same focal length will look across different camera systems, since a 50mm lens frames a very different scene on a full-frame body than it does on a smaller APS-C or Micro Four Thirds sensor.
How to Read Your Results
Diagonal Field of View
The angle measured corner-to-corner across the frame. This is the number most commonly quoted in lens marketing specs.
Horizontal Field of View
The angle measured left-to-right. This is the most intuitive number for understanding how wide a scene appears in a typical landscape-orientation shot.
Vertical Field of View
The angle measured top-to-bottom, useful for portrait-orientation framing or estimating headroom in a shot.
Sensor Diagonal
The physical corner-to-corner size of your sensor in millimeters, used to calculate the diagonal field of view and also the basis for a lens's "crop factor" relative to full frame.
Real-World Example
A 24mm lens produces very different fields of view depending on sensor size:
| Sensor | Dimensions | Horizontal FOV | Diagonal FOV |
|---|---|---|---|
| Full Frame | 36 × 24mm | 73.7° | 84.1° |
| APS-C | 23.5 × 15.6mm | 53.1° | 61.9° |
| Micro Four Thirds | 17.3 × 13mm | 40.6° | 48.5° |
The same 24mm "wide-angle" lens behaves like a moderate wide angle on full frame but frames noticeably tighter — closer to a standard lens — on a Micro Four Thirds sensor.
Tips for Understanding Field of View
- Smaller sensors narrow the field of view for the same focal length, often described using a "crop factor."
- Wider focal lengths (smaller mm numbers) increase field of view; longer focal lengths (bigger mm numbers) decrease it.
- Vertical FOV matters for headroom when composing portrait shots or vertical video.
- Manufacturer-published angle-of-view specs usually refer to the diagonal field of view.
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Last updated: August 2026 · Reviewed by: Simple Calculator Tools Editorial Team