Field of View Calculator — Horizontal, Vertical & Diagonal FOV

Field of view (FOV) is calculated using the formula: FOV = 2 × arctan(sensor dimension ÷ (2 × focal length)). The sensor dimension used determines whether you get horizontal, vertical or diagonal FOV. This assumes a rectilinear (non-fisheye) lens.

Two factors: focal length and sensor size. Shorter focal lengths give wider FOV. Larger sensors give wider FOV at the same focal length. A 50mm lens gives 39.6° horizontal FOV on full frame, but only 26.4° on an APS-C Nikon/Sony sensor (23.5 × 15.6 mm, a 1.53× crop) — about 27.0° on a nominal 24 × 16 mm 1.5× sensor.

The coverage area is the physical width and height of the scene captured at a given distance. At 10m with a 50mm full-frame lens, you capture approximately 7.2m × 4.8m of the scene (width = 36 × 10 ÷ 50 = 7.2m, height = 24 × 10 ÷ 50 = 4.8m). This is useful for planning group photos, architecture and event coverage.

The human eye has roughly 40-60° horizontal FOV for the central field of attention. A 43mm lens on full frame matches the sensor diagonal and gives about 53° diagonal FOV — considered the natural perspective. The classic 50mm lens is close at 46.8° diagonal.