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

Camera Lens Focal Length Calculator

A Camera Focal Length Calculator. This Calculates a Lens EFL for Cameras.
A Camera Focal Length Calculator. This Calculates a Lens EFL for Cameras.

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.

Read Our Camera Calculator & Optics Design Page, or Click below Use our Other Camera Calculators

Camera Field of View Calculator. FoV Calculator
Camera Depth of Field Calculator. DoF Calculator.
Camera Angle of View Calculator for Camera Lens Selection. AoV Calculator.

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.

Low Distortion 7.2mm M12 Lens

CIL872-F2.8-M12A650

A 7mm M12 Lens
A 7mm M12 Lens
7mm M12 Lenses
7mm S Mount Lens
$39.00

Small 2.5mm M12 Lens

CIL825-F2.4-M12ANIR

Stereographic M12 Lens
Stereographic M12 Lens
Stereographic M12 Lens
Stereographic M12 Lens
$39.00

Small 1.9mm M12 Lens

CIL819-F2.0-M12A650

2mm M12 Lens stereographic
2mm M12 Lens stereographic
2mm M12 Lenses stereographic
2mm M12 lens F2
$39.00

Surveillance?

Our low F#, high resolution lenses are suitable for 180° dome cameras, low light, and active IR illuminated scenes.

190°@9.1mm Fisheye M12 Lens

CIL231-F1.9-M12IR

3mm Mini Fisheye M12 Lens
3mm Mini Fisheye M12 Lens
3mm S Mount Fisheye Lens Raspberry Pi
Miniature Fisheye Lens
$99.00

195°@4.7mm Fisheye M12 Lens

CIL216-F2.2-M12A650

Fisheye Lens for 1/2.3
Fisheye Lens for 1/2.3
M12 Fisheye Lens for 20MP cameras
195 degree S Mount Lens for AR1820HS
$59.00

Fisheye 2.5mm CS Mount Lens

CIL725-F1.6-CSANIR

2.5mm Fisheye CS Mount Lens
2.5mm Fisheye CS Mount Lens
CS Mount Fisheye Lens FLIR
CS Mount Fisheye Lens Raspberry Pi High Quality
CCTV Fisheye Lens
$119.00

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.

Low Distortion 7.8mm M12 Lens

CIL078-F2.0-M12A650

8mm M12 Lens CIL078
8mm M12 Lens CIL078
8mm M12 Lenses
8mm S Mount Lens
Low Distortion 7.8mm M12 Lens
$59.00

Wide-Angle 4.8mm M12 Lens

CIL948-F2.0-M12B650

M12 Lens for AR0234
M12 Lens for AR0234
AR0234 S Mount Lens CIL948
5mm M12 Lens
$39.00

Wide-Angle 2.8mm M12 Lens

CIL329-F2.0-M12A650

IP69 AR0234 Lens CIl329
IP69 AR0234 Lens CIl329
Small M12 AR0230 Camera Lens
AR0233 Wide Angle M12 Lens
$39.00