How to Measure Your PD
Measure pupillary distance at home for clear, comfortable vision alignment.
What is Pupillary Distance (PD)?
Pupillary distance (PD) is the distance between the centers of your pupils, measured in millimeters (mm). A correct PD helps align the optical center of your lenses for clearer, more comfortable vision.
Why It Matters
Accurate PD distance improves lens centering and helps reduce visual discomfort.
How to Measure Your PD
Prefer a visual walkthrough? This short video shows how to measure pupillary distance with a PD ruler, plus tips to keep your PD measurement consistent.
Printable PD Ruler
Print this at 100% / Actual size on A4 paper or US letter paper. For the most accurate results, measure 2–3 times and use the average.
Note: Please print at 100% size on A4 / US letter paper.
How to Measure Your PD at Home
Follow these four steps with a printed PD ruler. Work in good lighting, hold the ruler level, and keep your face relaxed.
Step 1
Stand about 8 inches (20 cm) from a mirror. Keep your head level and look straight ahead.
Step 2
Close your right eye. Align the “0” mark on the ruler with the center of your left pupil.
Step 3
Close your left eye. Read the millimeter number that lines up with the center of your right pupil.
Step 4
If you need dual PD, measure each eye separately (OD/OS) and enter both numbers.
The average adult PD is usually between about 54 mm and 78 mm. For the most accurate result, measure 2–3 times and use the average.
Single vs. Dual PD (OD/OS)
Use single PD when checkout shows one PD field. Use dual PD when checkout asks for two PD fields (right/left).
| Type | What It Looks Like | When To Use |
|---|---|---|
| Single PD | One number (e.g., 63mm) | When checkout shows one PD field |
| Dual PD | Two numbers (e.g., OD 31mm / OS 32mm) | When checkout asks for two PD fields (right/left) |
Can You Measure PD Online?
Yes. Online tools can help you estimate your pupillary distance. For best accuracy, especially with a stronger prescription, consider getting PD measured by an eye care professional.
Option 1
Use a photo tool (phone or webcam). Use a standard card for scale, keep your face centered, look straight ahead, and use good lighting.
Option 2
Use a printable PD ruler (recommended). Print at 100% actual size, then follow the step-by-step guide above.
Option 3
Ask a friend to measure for you. This can improve accuracy because you can keep both eyes open and your head steady.