This Camera Focal Length Calculator finds the Lens Focal Length From a Field of View
Camera Lens Focal Length Calculator


This effective focal length calculator helps you select a lens to use with your camera. The calculator takes your target field of view (angle of view) and camera specification then provides the required lens EFL.
The calculator uses the camera lens focal length equation. This formula is different than the lens maker's equation which is intended for simple thin lens elements.
The Optical Effective Focal Length (EFL) should not be confused with the Mechanical Back-Focal Length (BFL). The EFL determines the field of view of the camera while the BFL determines whether a lens will focus on a camera.
Building a Camera? Use Our Wide-Angle Lens Calculator or Browse Below
Aerial Robotics?
Our light-weight, miniature lenses are ideal for collision avoidance, long-distance viewing, and end-customer viewing.
Surveillance?
Our low F#, high resolution lenses are suitable for 180° dome cameras, low light, and active IR illuminated scenes.
Surveillance?
Our low F#, high resolution lenses are suitable for 180° dome cameras, low light, and active IR illuminated scenes.
Consumer / AR+VR?
Our high resolution fisheye lenses will let you design 360° cameras and and stereographic lenses are equivalent to "GoPro" lenses.
Video Conferencing?
Our wide-angle, low distortion, high resolution M12 lenses result in optimal object deformation without post-processing.
Video Conferencing?
Our wide-angle, low distortion, high resolution M12 lenses result in optimal object deformation without post-processing.
Mobile Robotics?
Find a low F# or low distortion lens to optimize your computer vision framerate.