Enter the measurements for the distance between your pupils into the calculator to determine your Pupillary Distance (PD).

Pupillary Distance Calculation Formula

The following formula is used to calculate your Pupillary Distance (PD).

Total PD = Left Pupil Distance + Right Pupil Distance

Variables:

  • Total PD is the combined distance between your pupils (mm)
  • Left Pupil Distance is the distance from the center of your left pupil to the bridge of your nose (mm)
  • Right Pupil Distance is the distance from the center of your right pupil to the bridge of your nose (mm)

To calculate the total PD, add the left pupil distance to the right pupil distance.

What is Pupillary Distance?

Pupillary Distance (PD) is the measurement of the distance between the centers of your pupils. It is an essential measurement for creating custom eyeglasses or contact lenses. Properly measured PD ensures that the lenses’ optical centers align with your pupils, providing clear and comfortable vision.

How to Measure Pupillary Distance?

The following steps outline how to measure your PD:

  1. Stand in front of a mirror and hold a ruler against your brow.
  2. Close your right eye and align the ruler’s zero mark with the center of your left pupil.
  3. Without moving the ruler, close your left eye and open your right eye.
  4. Note the measurement from the ruler’s zero mark to the center of your right pupil. This is your total PD.
  5. For dual PD, measure the distance from the bridge of your nose to the center of each pupil individually.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Left Pupil Distance = 31.5 mm

Right Pupil Distance = 32