Horizontal Filed Of View (HFOV) and Effective Focal Length (EFL) calculator

    The following calculator computes the Horizontal Field of View (HFOV) or Effective Focal Length (EFL) of a camera and lens system, for any sensor format.

    Upon completion of the calculation, using the final values, you will be able to search for the appropriate IR lens to meet your requirements.

    Please note that the results of the calculator are not exact, as they are based on the paraxial approximation, which does not take lens distortion into account. Errors in wide-FOV lenses could be significant.

     HFOV Calculator

    Number of horizontal pixels

    Pixel pitch



    Effective focal length in millimeters