What Do the Numbers on My Glasses Mean? A Full Explanation

Have you ever looked inside your glasses and seen a bunch of numbers? You might wonder what do the numbers on glasses mean. Don’t worry, you’re not alone!

These numbers are not about your eyesight. They don’t come from your eye doctor. They are all about how your glasses fit your face. In this guide, we’ll help you understand the glasses numbers' meaning and how they help you pick the best glasses for your face.

Where to Find Your Frame Measurements

You can find the numbers on the inside of one of the arms of your glasses. The arms are the long parts that go behind your ears.

Sometimes, the numbers are on the bridge, which is the part that sits on your nose.

Decoding the Three Numbers: Eye, Bridge, and Temple

You will usually see three numbers like this: 52□18-140. All of these are in millimeters (mm). Let’s break down how to read glasses measurements.

The First Number: Eye Size (or Lens Width)

This is the first number. It tells you how wide one lens is.

What it does: It helps show how big the glasses will look on your face.

The Second Number: Bridge Width

This is the middle number. It tells you how wide the space is between the two lenses — the part that goes over your nose.

Why it matters: It helps the glasses sit right on your nose. If it’s too small, they might pinch. If it’s too big, they might slip.

The Third Number: Temple Length

This is the last number. It tells you how long the arms of your glasses are.

Why it matters: It helps the glasses fit nicely behind your ears so they don’t fall off.

How Frame Glasses Measurements Affect Your Look and Comfort

The Real Key to Fit: Calculating Total Frame Width

This is how wide your glasses are from one end to the other. It’s a big deal when picking glasses that fit your face.

Here’s a simple way to figure it out: (Eye Size x 2) + Bridge Size = Total Width

Example:
If your glasses say 52□18-140,
then (52 x 2) + 18 = 122 mm wide.

That’s a good size if your face is about that wide, too.

Lens Height: Why It Matters for Your Style and Lenses

This tells you how tall the lens is from top to bottom.

Why it matters: Some glasses need taller lenses for bifocal or progressive lenses (if you use those). Also, the shape can change how your face looks — round, square, or more modern.

The Nuance of Bridge Fit: High vs. Low Bridges & Nose Pads

Some people have high noses. Some have low noses. That’s why the spot where the bridge sits matters.

 High bridge: The glasses will sit lower.

 Low bridge: The glasses will sit higher.

Also, some glasses have adjustable nose pads. These help you move the frame for better comfort. These are great if your glasses slide down a lot. Plastic frames don’t usually have these.

Read more about low bridge fit here.

How to Find Your Perfect Fit: 3 Easy Methods

Method 1: Use Your Current Glasses

Look at the numbers on a pair that already fits you well. Use them when buying new ones.

Method 2: The Credit Card Trick

Hold a card under your eye, across your nose.

 If the card is wider than your eye, you need a small frame.

 If the card is the same size, go for a medium frame.

 If the card is narrower, you need a large frame.

Method 3: The Printable Ruler Method

You can use a printable ruler to measure in millimeters. This helps you check how wide your glasses should be. Here is a Free Printable Sizing Guide & Rule.

Your Complete Eyeglass Markings FAQ

What are the other numbers and symbols on my frames?

Besides the size, you may see other things:

 Model number: This shows the style or type.

 Color code: A shortcode for the frame color.

 CE mark: This means the glasses meet safety rules in Europe. It’s a good sign.

What happens if my glasses are the wrong size?

If your glasses are too small or too big, you might notice:

 They slide off.

 They pinch your nose.

 They give you a headache.

 They just look wrong on your face.

Is Pupillary Distance (PD) part of the frame size?

PD is not printed on your glasses. It’s from your eye doctor. It shows how far apart your eyes are. It helps center your lenses the right way. It’s not part of the frame numbers.

Frame Fit vs. Vision Correction: A Final Clarification

Let’s make it clear one more time:

 Frame numbers = How your glasses fit your face

 Prescription numbers = How your glasses help you see better

Want to learn more about your prescription? Click to learn How to Read Your Eyeglass Prescription.

Conclusion

Now you know what those numbers on glasses frames mean!

The first number is the eye size. The second is the bridge width. The third is the temple length.

These numbers help you find glasses that feel good and look great. Next time you shop for glasses, you’ll be ready to find the perfect pair.

You’ve got this! Now, go pick out glasses that fit you just right. Want help choosing? Check out our top picks for the best-fitting frames!