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How to Measure Your Pupillary Distance (PD) at Home

A simple guide to getting an accurate measurement for your next pair of glasses.

When it comes to ordering prescription glasses, one tiny but powerful number can make all the difference: your Pupillary Distance (PD). It's the distance between the centers of your pupils, measured in millimeters, and it ensures that your lenses are positioned correctly in front of your eyes. A properly measured PD leads to sharper vision, less eye strain, and more comfortable glasses.

If you don't have your PD on hand, don't worry — measuring it at home is simple with a few basic tools. Here's a step-by-step guide to help you get it right.

What You’ll Need:

  • A mirror
  • A millimeter ruler (you can print one or use a regular one)
  • A steady hand
  • A friend (optional but helpful!)

Video Tutorial

Illustration of a person measuring their PD in a mirror

How to Measure Your PD by Yourself

  1. Get Your Ruler Ready: Use a ruler that measures in millimeters. If you're using a printed ruler, make sure it's printed at 100% scale.
  2. Stand in Front of a Mirror: Position yourself about 8 inches (20 cm) away from a mirror, standing straight and relaxed.
  3. Align the Ruler: Hold the ruler against your forehead, just above your eyes, and close your right eye. Line up the zero (0) mark with the center of your left pupil.
  4. Take the Measurement: Without moving the ruler, close your left eye and open your right eye. Read the number that lines up with the center of your right pupil. That's your PD!
  5. Double-Check: Repeat the process a few times to make sure you're getting a consistent number. If you get slightly different results, take the average.
Illustration of a person helping another measure their PD

How to Measure Your PD with Help

  1. Get Comfortable: Sit down and focus on a point about 10 to 20 feet away to keep your eyes steady and relaxed.
  2. Ruler Placement: Have your helper rest the ruler flat against your forehead, aligning the 0 mm mark with the center of your right pupil.
  3. Measure Carefully: While you continue looking at the distant object, your helper should measure the distance to the center of your left pupil. This number is your PD.

Types of PD Measurements

  • Single PD: A single number, like 63 mm, measuring the total distance between your pupils. This is common for single-vision lenses.
  • Dual PD: Two measurements, such as 31 mm and 32 mm, representing the distance from each pupil to the bridge of your nose. This is often needed for progressive or bifocal lenses.

Typical PD Ranges

  • Adult Range: 54–74 mm
  • Average for Women: About 60 mm
  • Average for Men: About 64 mm

(Keep in mind: these are averages — your unique PD might be different, and that's perfectly normal!)

Why Getting Your PD Right Matters

A PD that's off by even a few millimeters can cause:

  • Eye strain
  • Blurry vision
  • Headaches
  • General discomfort with your glasses

Taking a few minutes to get this measurement right ensures that your lenses align properly with your eyes, giving you the clearest, most comfortable vision possible.

With just a mirror, a ruler, and a little patience, you can easily measure your PD at home — no special equipment or appointments needed!