Guide To Measure PD

Measure Your Pupillary Distance (PD)

You will be asked to mention your PD with your prescription while placing an order for eyeglasses. Learn more about your pupillary distance here.

What is Pupillary Distance?

  • PD is the distance between the centers of your pupils.
  • An average adult’s PD is between 54-74 mm.
  • For an average kid, it is between 43-58 mm.

Why We Measure PD?

Your PD measurement is used to help the prescription lenses to be centralized correctly. Thus, it should be as accurate as possible.

Eye Winsome  Printable PD Scale

Your prescription may tell you your PD but if it is not available, use your friend or a mirror to help you figure it out. You can easily download the PD Ruler from here.


How to Measure Your PD

You can ask your ophthalmologist to include you PD measurement on your prescription. Alternately, you may use the following steps to help you figure it out yourself.

Step 1: Print the Eye Winsome PD Scale given above.

Step 2: Stand straight about 8 inches for from a mirror.

Step 3: Hold the ruler against your eyebrow.

Step 4: Close your right eye and keep the ruler’s zero to the center of the left pupil.

Step 5: In the same position of your face and scale, close your left eye and open the right one.

Step 6: Note down the mm reading that is indicating the center of your right pupil.
This is your Pupillary Distance (PD).

Important Notes:

  • Measure your PD 3, 4 times to get accurate results.
  • Range of Adult’s PD: 54-74 mm
  • Range of Child’s PD: 43-58 mm


Step 1: Keep both of your eyes open.

Step 2: Ask your friend to put the zero of the scale on the center of any of your pupils.

Step 3: Measure the distance between the centers of both pupils.


  • Keep your eyes as still as possible.
  • Do not look at the person who is measuring but straight ahead.

Single PD and Dual PD

Single PD is the pupillary distance between the centers of your pupils, which can be a distance PD or near PD. Distance PD can be used to order any type of prescription glasses except reading glasses. Read below to learn how to calculate near PD for reading glasses.

Dual PDor monocular PD, consists of two numbers and is the distance between the centers of each pupil to the bridge of the nose. Dual PD is usually written in the following notation: 32/30. The first number is always the right eye (OD) measurement, and the second number is the left eye (OS).

How Do You Calculate Near PD For Reading Glasses?


You can calculate Near PD for reading glasses by subtracting 3 mm from your distance PD. For example, if your distance PD is 63 mm, then your near PD is 60 mm.

If you are using Dual PD to calculate near PD, then subtract 1.5 mm from each eye’s measurement. For example, if your dual PD is 33/31 mm then your near PD would be 31.5/29.5 mm.

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