Field of View Calculator

See the horizontal, vertical and diagonal angle of view for a lens on your sensor, plus the real-world frame size captured at any distance. Calculated in your browser.

Diagonal angle of view

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Horizontal angle-
Vertical angle-
Frame width at distance-
Frame height at distance-

Show the math

Angle of view comes from the sensor dimension d and focal length f; frame coverage scales linearly with distance s:

angle = 2 · arctan(d ÷ 2f)

frame size = (d ÷ f) · s

Sensor width and height are taken from the selected format. All math runs in your browser.

What this does

A field of view calculator shows the horizontal, vertical, and diagonal angle of view for a lens on your sensor, plus the real-world frame size captured at any distance.

How to use it

  1. Pick your sensor or format.
  2. Enter the focal length.
  3. Enter the subject distance.
  4. Read the angles and frame size.

How it works

Horizontal uses sensor width, vertical its height, diagonal its diagonal. Frame size scales linearly: frame = (sensor ÷ focal length) × distance.

angle = 2 × arctan(sensor ÷ (2 × focal length))

Understanding your result

The angle tells you how much of a scene the lens takes in, wider for landscapes, narrower for compression and reach, while the real-world frame size shows exactly what fits at a given distance. Use the frame size to plan a shot before you arrive: it tells you how far back to stand to fit a subject, which is invaluable for tight spaces or knowing if a lens will reach.

Example

A 35 mm lens on full frame sees about a 54° horizontal angle of view.

Sources & methodology

Last updated .

Frequently asked questions

How is angle of view calculated?

Each angle is 2·arctan(sensor dimension ÷ 2·focal length). Horizontal uses sensor width, vertical uses sensor height, and diagonal uses the sensor diagonal.

What is the frame size at a distance?

It is how wide and tall a scene the lens captures at a given subject distance, scaling linearly: frame size = (sensor dimension ÷ focal length) × distance.

Is anything uploaded?

No. Everything is computed in your browser — nothing you enter is sent anywhere.