Measure PD
Kid-Friendly Method
Multiple Readings
How to Measure a Child's PD and Frame Size

Kids can't always sit still for measurements the way adults can -- here's how to get it right anyway.

Measuring PD for Kids

The same general methods used for adults apply to children, though patience and a helper make a real difference. Our camera-based PD tool can work for kids who can hold reasonably still for a few seconds, or a simple ruler method works as a backup.

1
Have Them Sit Facing You

At eye level, in a well-lit room, looking straight ahead at a point behind you (like your nose or a spot on the wall).

2
Use the Camera Tool If Possible

Our PD measurement tool auto-captures once it detects a stable, centered face -- often easier for kids than holding a ruler steady themselves.

3
Or Measure Manually

With a millimeter ruler, measure from the center of one pupil to the center of the other while they look straight ahead.

4
Take Multiple Readings

Especially with kids, take 2-3 measurements and use the most consistent result, since kids may shift position between attempts.

Measuring Frame Size for a Child's Face

Children's face widths vary widely by age, so rely on an actual measurement rather than age-based size charts alone. Follow the same method in our full frame size guide, measuring face width at the temples, and compare to size labels rather than guessing based on age.

Don't size up 'to grow into' An oversized frame slides, sits crookedly, and is one of the most common reasons kids stop wearing their glasses. A properly fitted frame now is worth replacing again later as they grow.
Frequently Asked Questions
Can I use the same PD tool for kids as adults? +
Yes, our camera-based PD tool works for anyone who can hold reasonably still and look at the camera for a few seconds.
How often does a child's PD change? +
PD changes gradually as children grow, so it's worth re-measuring at each new glasses order rather than reusing an old measurement.
What if my child won't sit still for a measurement? +
Try a favorite show or toy to hold their attention briefly, or ask your eye doctor to include the measurement during their eye exam.
Should I size up a frame for a growing child? +
No, sizing up leads to poor fit and reduced willingness to wear glasses -- size accurately now and replan for a new size later as needed.
More Helpful Guides
A great fit for growing kids

Accurately sized frames for kids, starting at $49, with free shipping and returns.