Decoding Eyewear: What Are the Numbers on My Glasses Frame?

It’s a commonly asked question: What are the numbers on my glasses? These 3 little numbers can actually be immensely helpful in understanding the fit of your glasses and in picking out your next pair! 

If you’re not already familiar, take a peek at the inner side of your glasses’ temple (or arm) and let’s break it down!

What Are Those Numbers?

Lens Width

The first number is the lens width of one side. This number represents the width of each lens measured horizontally, in millimeters. 

It typically ranges from 40mm to 62mm.

At SpecTats, we label our frames as such:

48-51mm - Small

52-55mm - Medium

56+mm - Large

Bridge Width

The second number is the bridge width. This number is the distance between the lenses, specifically the gap where the frames rest on your nose. 

It’s usually between 14mm and 24mm.

Temple Length

The third number is the temple length. The temple length indicates the length of the arms or temples, extending from the hinge to the tip. 

This measurement typically ranges from 120mm to 150mm on average.

What Other Measurements Might You Want to Know?

Lens Height

Occasionally, you might find a fourth number that denotes the height or depth of the lens. This is especially common for taller frames. 

Frame Width

The frame width is the overall width of the entire frame. Although this will not be found on the temple of your glasses, you can easily calculate or measure this number. 

In many cases, you can just take the lens width and double it and then add the bridge width. This gives you a pretty good ballpark number and then if the glasses have any additional hardware that extends off the sides of the frame or the frame is thicker, just add an additional few millimeters to get this number. 

This number typically ranges from about 125mm to 150mm.

What Does This Mean to You?

Understanding these measurements is crucial for teaching you how to find glasses that fit your face and provide optimal vision correction. They also help when shopping for your unique glasses frames online, as you can use these numbers to find frames that match the size and fit you prefer.

If you absolutely love the way your frames fit your face, look for frames with similar measurements. Most people go by this simple rule: your glasses frames should be the width of your face or a little wider.

On the flip side, if something just isn’t right with how your current frames are feeling, these numbers might give you an indication on where you need to make adjustments. 

For example, if your glasses seem too tight on the sides of your head, you may need wider frame glasses. Take a look at that first number, and then add a few millimeters. This will add several millimeters between the two lenses to give you some extra breathing room. 

For another example, maybe your glasses are bothering the tops or back of your ears. This could be an indication that the temple is not long enough. Take a look at the third number in the set on your current glasses, and then again, add a few millimeters. This should help you get a temple length that is more comfortable. 

Why It Matters

Wearing glasses that are the right size not only ensures comfort but also improves vision accuracy. Ill-fitting frames can cause discomfort, headaches, or even affect how well you see through your lenses.

And it’s not just about comfortability; it’s about what looks good on your face. If you have a narrow face and are wearing glasses that are too wide, they may take over your face and look kind of silly.

Alternately, if you have a wider face, but you’re wearing frames that are narrower, it will likely cause the temples to be stretched out and rather than going behind your ears parallel to one another, they would be turned outward and also look kind of silly. 

Every glasses lens has what’s called a “sweet spot” that you mostly look through during everyday life. If your frames, and therefore lenses, are too big or too small, your eyes may be missing that “sweet spot” for optimal vision.

Wrapping It Up

Next time you glance at those numbers on your frames, remember they aren’t just random digits; they hold the blueprint to the perfect fit for your glasses. Understanding these measurements helps you choose frames that feel as good as they look!

Now that you're in on the secret code of eyewear numbers, decode those digits, find your perfect fit, and rock those frames with confidence!