Measure your PD—free online tool

The easiest way is with our free online PD measurement tool—it uses your computer camera to calculate your pupillary distance quickly and accurately. Grab any standard-sized card, find some good lighting, and follow the on-screen steps. You can also measure your PD in The Framery app, which walks you through the same process from your phone. No doctor’s appointment needed.

Pretty accurate. In testing, 95% of scans were within 1mm of the medical standard, and 100% were within 2mm—well within the safe zone for prescription lenses. For context, the medical standard for PD accuracy is ±2.5mm.

Nope. Your PD Reader results are ready instantly and are accurate enough to use for your prescription glasses order—no follow-up needed.

In the U.S., our PD Reader is FDA-listed as a non-medical device. In some regions—including the EU, UK, Canada, and Australia—it’s registered as a Class I Medical Device. Either way, it’s been tested extensively for accuracy and is safe to use for ordering prescription glasses online.

On desktop, use Safari, Chrome, or Firefox. On mobile, use Safari for iPhone or Chrome for Android. Or skip the browser altogether and measure your PD directly in The Framery app—it’s built for this.

A standard-sized card gives the tool a reference for scale so it can measure your pupillary distance accurately. There’s never a need to use a credit card (please don’t, really). Gym card, library card, membership card—they all work great.

We only access your camera during the scan and take privacy seriously. Our tool automatically blurs any details on your card so they can't be recognized, and your image is never linked to any personally identifiable information. For more, check out our Privacy Practices.

There are a few things that usually do the trick. Make sure your audio is on—you'll hear prompts that guide you through. Look straight into the camera with your eyes clearly visible. (Sorry, bangs—you'll need to step aside for this one.) Place your card right above your eyebrows, and hold it at the corners. Good lighting and a clean camera lens help too. If you're still having issues, contact us! We can help.