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.

Telephoto 12mm M12 Lens

CIL125-F2.4-M12IR

Telephoto 12mm M12 Lens
Telephoto 12mm M12 Lens
Telephoto M12 Lens 12mm
Telephoto 12mm M12 Lens
Telephoto 12mm S-Mount Lens
$29.00

Telephoto 35mm M12 Lens

CIL350-F2.4-M12A650

35mm M12 Lens
35mm M12 Lens
35mm Board Mount Lens
35mm S Mount Lens
$59.00

Telephoto 26mm M12 Lens

CIL260-F2.0-M12IR

25mm M12 Lens
25mm M12 Lens
25mm S Mount Lens
25mm lens for FLIR Cameras
$79.00

Surveillance?

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

200°@6.3mm Fisheye M12 Lens

CIL219-F2.5-M12IR

200° M12 Fisheye Lens
200° M12 Fisheye Lens
200° Mini Fisheye Lens
Mini M12 Fisheye Lens
$79.00

Mid-Range 7.6mm M12 Lens

CIL080-F1.8-M12IR

8mm 1/1.7
8mm 1/1.7
8mm S-Mount Lens for 4K+ sensors
8mm M12 Lens for 12MP+ 1/1.7
$59.00

200°@5.7mm IP67 Fisheye M12 Lens

CIL217-F2.7-M12A650

Mini Fisheye S Mount Lens
Mini Fisheye S Mount Lens
Tiny Fisheye Lens
Miniature Fisheye
$39.00

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.

GoPro 3.0mm M12 Lens

CIL331-F2.5-M12A660

3.1mm Wide Angle M12 Lens
3.1mm Wide Angle M12 Lens
3mm S-Mount Lens
3mm M12 Lens
$39.00

No Distortion 3.9mm M12 Lens

CIL039-F2.8-M12IR

A 14MP 4mm M12 lens that is wide angle no distortion.
A 14MP 4mm M12 lens that is wide angle no distortion.
A 3.9mm M12 Lens pictured with the Raspberry Pi High Quality
A 4K M12 Lens for the Raspberry Pi High Quality Camera. CIL039.
$39.00

230°@4.5mm Fisheye M12 Lens

CIL213-F2.3-M12A660

230 degree M12 Fisheye lens
230 degree M12 Fisheye lens
Ultra-wide fisheye lens with 230 degree field of view
230degree mini fisheye lens
$99.00

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.