Before measuring your PD at home, it’s worth checking your eyeglass
prescription. Sometimes your optometrist will include your PD on the
prescription, or you can simply ask them to write it down during your exam. If
you don't have it don’t worry you can easily measure it yourself
using the steps below.

Option 1: The Fastest Way – Using a Smartphone App

Smartphone apps and online tools make PD measurement quick and simple:      

1. Get a trusted app from your app store.      

2. Follow the instructions carefully – most will ask you to take a selfie
while holding a standard object (like a credit card) near your eyes for scale.      

3. Snap the photo as directed.      

4. The app automatically calculates your PD in millimeters.

Why this works best: You don’t need a second person or a ruler, and it’s
accurate enough for ordering glasses online.

Option 2: Mirror + Ruler Method

If you prefer a hands-on approach, you can measure your PD with a mirror and
a ruler:      

1. Stand about 8 inches (20 cm) from a mirror in a well-lit room.      

2. Place a millimeter ruler across your brow.      

3. Close your left eye and align the 0 mm mark with the center of your
right pupil.      

4. Without moving the ruler, close your right eye and open your left.      

5. The number that lines up with your left pupil is your PD.

Pro tip: Take the measurement a few times and use the average to be sure
it’s accurate.

Quick Tips for Accuracy      

• Ask a friend to help for a steadier measurement.      

• Always measure in millimeters.      

• Avoid using soft surfaces like paper towels or your hand for scale.