Free Field of View Calculator

Field of view is the angular extent of the scene a lens captures, set by the sensor size and focal length. Angle of view = 2 × atan(sensor ÷ (2 × focal length)). See exactly how much of the scene any lens sees on your camera — before you buy or frame.

Your setup

Results

Horizontal FOV
across the frame
Vertical FOV
top to bottom
Diagonal FOV
corner to corner
35 mm equiv.
full-frame focal length
Scene width @ distance
left to right
Scene height @ distance
top to bottom
camera

How field of view works

Field of view (angle of view) is set by two things: the sensor dimensions and the focal length. A 50 mm lens on full frame sees 39.6° horizontally; the same lens on APS-C sees about 26.5° — which is why crop sensors "crop" the frame (1.5× crop ≈ 75 mm equivalent).

The 35 mm equivalent is the focal length that would give the same framing on a full-frame body. It's how photographers compare lenses across sensor sizes: Micro 4/3 has a 2× crop, APS-C ≈ 1.5× (Canon ≈ 1.6×), phones ≈ 5-7×.

Worked example

You're choosing a lens for an indoor shoot and the room is 4 m across. With a full-frame body, a 24 mm lens (73.7° horizontal) frames the whole wall from about 2.8 m back, while a 35 mm (54.4°) needs ~4 m — the calculator tells you exactly which lens fits before you carry it there. The same math works in reverse for video: pick your shot size, then check whether your zoom range covers it at the working distance. This is also how you compare across sensor formats — a 23 mm lens on APS-C frames like 35 mm on full frame, and the calculator shows both angles side by side.

Field of view reference table (focal length × sensor)

Horizontal angle of view in degrees for each focal length and sensor format. Divide-by-two, roughly: a 24 mm lens on full frame sees about 74°, and the same lens on APS-C sees about 52° — which is why a 24 mm on a crop body frames like a 36 mm on full frame.

Focal lengthFull frame
36 × 24 mm
APS-C (1.5×)
23.5 × 15.6 mm
APS-C Canon (1.6×)
22.3 × 14.9 mm
Micro 4/3
17.3 × 13 mm
1-inch
13.2 × 8.8 mm
14 mm104.3°80.0°77.1°63.4°50.5°
16 mm96.7°72.6°69.7°56.8°44.8°
20 mm84.0°60.9°58.3°46.8°36.5°
24 mm73.7°52.2°49.8°39.6°30.8°
28 mm65.5°45.5°43.4°34.3°26.5°
35 mm54.4°37.1°35.3°27.8°21.4°
50 mm39.6°26.4°25.1°19.6°15.0°
85 mm23.9°15.7°14.9°11.6°8.9°
100 mm20.4°13.4°12.7°9.9°7.6°
135 mm15.2°9.9°9.4°7.3°5.6°
200 mm10.3°6.7°6.4°5.0°3.8°
300 mm6.9°4.5°4.3°3.3°2.5°
400 mm5.2°3.4°3.2°2.5°1.9°

Values are horizontal angles of view computed as 2·atan(sensor width ÷ (2 × focal length)), rounded to 0.1°. Vertical and diagonal angles, and the 35 mm equivalent for your exact body, are in the calculator above.

📐 Rule of thumb: doubling the focal length halves the angle of view. 24 mm → 74°, 48 mm → 37°, 96 mm → 18°. Equally, moving a lens from full frame to Micro 4/3 (2.0× crop) halves it again.

Related tools & guides

Camera Sensor Sizes

Full sensor dimensions and crop factors, explained.

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Astro Pixel Scale Calculator

Arcsec/pixel sampling for your camera + scope.

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Focal Length Explained

What focal length actually does to your frame.

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Field of view FAQ

What's the difference between FOV and focal length?

Focal length is a property of the lens; field of view is the result on a given sensor. The same lens gives different FOV on different bodies. That's why "35 mm equivalent" exists.

How is field of view calculated?

FOV = 2 × atan(sensor dimension ÷ (2 × focal length)), in degrees. Horizontal uses sensor width, vertical uses height, diagonal uses the diagonal.

Does field of view change when I crop in post?

Yes — cropping changes the effective sensor area, so the FOV narrows exactly like using a longer lens. The calculator's distance fields show you the scene dimensions your final crop will cover.