Field of View Calculator for Photography

Summary

Field of view (FOV) tells you how wide a scene your lens captures at a given focal length and sensor size. Enter your focal length and pick a sensor format — or type a custom sensor width and height — and the calculator returns the horizontal, vertical, and diagonal angles of view using the standard 2 × arctan(sensor / 2f) formula. Crop-factor equivalents are shown alongside so you can compare across formats.

How it works

1. Enter your lens focal length in millimeters.
2. Select a sensor size preset (full-frame, APS-C Canon, APS-C Nikon/Sony, Micro Four Thirds, 1-inch, or custom).
3. For a custom sensor, type the width and height in millimeters.
4. The calculator instantly shows horizontal, vertical, and diagonal FOV in degrees.
5. The equivalent full-frame focal length (accounting for crop factor) is displayed below the results.

Use cases

• Choose the right focal length before buying a new lens.
• Plan a shoot and predict how much of a scene a lens will capture.
• Compare how the same focal length behaves on different sensor formats.
• Understand crop-factor impact when switching camera systems.
• Calculate FOV for astrophotography to frame a specific sky region.
• Pre-visualize real-estate or architecture shots for wide-angle coverage.

Frequently Asked Questions