Finding glasses that fit perfectly doesn’t have to be a guessing game. Our simple guide will help you measure your face and understand frame sizes so you can shop with confidence.
The 3 Magic Numbers on Your Glasses
Every pair of glasses has three key measurements printed on the inside of the temple (the arm that goes over your ear). They usually look something like this: 52 18 140.
Lens Width
The horizontal width of one lens at its widest point (in mm). This determines how the glasses will look on your face
Bridge Width
The distance between the two lenses (in mm). This affects comfort and prevents glasses from sliding down your nose.
Temple Length
The length of the entire arm from hinge to end (in mm). This determines how the glasses fit behind your ears.
How to Measure Your Face (No Old Glasses Needed)
If you don’t have an old pair to check, you can measure your face directly with a ruler and some simple techniques.
1 Measure Your Pupillary Distance (PD)
This is the distance between your pupils, which ensures the optical center of the lenses is correct for you.
How to measure:
- Stand about 8 inches from a mirror
- Hold a ruler flat against your browline
- Close your right eye and align the ruler’s “0” mark with the center of your left pupil
- Without moving the ruler, close your left eye and open your right eye
- The number aligned with the center of your right pupil is your PD
2 Find Your Ideal Frame Width
Your glasses should be slightly narrower than your face width.
How to measure:
- Look straight into a mirror
- Measure the distance from one temple to the other, across your nose
- Choose frames that are slightly narrower than this measurement
3 Determine Temple Length
The temple should fit comfortably from the hinge to behind your ear.
How to estimate:
- Measure from your temple (just in front of your ear) to where the arm would curve behind your ear
- Most temples range from 135mm to 150mm
The Perfect Fit Checklist
Before you finalize your purchase, make sure your glasses pass these simple tests:
- The Eyebrow Test: The top of the frames should not sit higher than your eyebrows
- The Cheek Test: Your glasses should not touch your cheeks, even when you smile
- The Width Test: The frames shouldn’t extend beyond the widest part of your face
- The Comfort Test: The nose pads should rest comfortably without pinching, and the temples shouldn’t press too tightly against your head
