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How to use the PD Ruler

PD (Pupillary Distance)

PD is the distance measured in millimeters (mm) between the centers of each pupil, and is used to make prescription eyeglasses.

PD (Pupillary Distance)

Preparing the ruler

  • Print this page

    Print this page

    Without scaling, at 100%.

  • Double-check scale

    Double-check scale

    By measuring against a standard mm ruler, or the credit card diagram below.

    Credit card length
  • Fold the ruler

    Fold the ruler

    Along the dotted line.

Measure your PD

  • Position


    Stand approximately 8 inches (20cm) away from a mirror, or ask someone to measure for you.

  • Measure


    Place the ruler directly over the center of your right pupil so that the ruler is horizontal (place against forehead for added stability).

  • Repeat


    Look straight ahead and measure the distance between your left and right pupils. Repeat for accuracy and use an average for your final measurement.

PD ruler size

This is the exact size that your PD ruler should be (don’t scale it up or down when you go to print).

PD ruler size
Preview printable ruler