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What Size Sunglasses Do I Need? Understanding Sunglasses Sizes

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woman wearing square sunglasses

The last thing that you want to do is get a pair of sunglasses only to find out that they don’t fit. The best way to ensure that this doesn’t happen is to figure out what size sunglasses you need in the first place!

But how do you figure out what size sunglasses you need, and what do all those numbers mean, anyway? There are three different measurements that you’ll need to account for to get a secure fitment. Here, we break down each one and how you can figure out what size of sunglasses you need.

Understanding Sunglasses Sizes

When you’re looking at sunglasses sizes, there are three numbers to look at. The exact locations will vary but each has its own unique range.

The first number is the “eye size.” This ranges anywhere from 40 to 60, and it refers to the size of each lens in millimeters.

The next number is the bridge size, and it ranges between 14 and 24. This is the distance between the two lenses, once again in millimeters.

The final number is the temple size, and this number ranges between 120 and 150. This number refers to the distance of the side pieces of the glasses from the frame to the end of the piece. This is the part that rests on the side of your head and curves behind your ears.

various sunglasses on the table
Image By: Sefton N Brown Jnr, Shutterstock

Measuring for Sunglasses Sizes

Now that you understand the three main measurements that manufacturers use to break down sunglass sizes, it’s time to figure out what measurements you specifically need.

Fortunately for most people, it’s a straightforward process: Take a straight ruler, and measure across your face, from temple to temple.

In the United States, most people take this measurement in inches, but you’ll need to convert it to millimeters to get accurate results for your sunglasses.

Once you convert your figures, you can use the following guide to figure out what lens size to use, as the bridge size usually corresponds. However, if you don’t have typically proportioned facial dimensions, you might need to take each measurement individually and special order your sunglasses for a proper fitment.

man wearing sunglasses
Image By: Piqsels
Facial Measurement (Inches) Recommended Lens Size (Millimeters)
4.5 to 5.1 49 to 54
5.25 to 5.5 55 to 57
5.75 to 6.25 58 to 63

What Size Is Standard Size Sunglasses?

While the exact measurements for “standard” sunglasses are going to change from manufacturer to manufacturer, most of the time, the lens measurement is around 55 to 56 millimeters. A temple measurement between 135 and 150 is most common.

That said, it’s always best to take a close look at what each company offers and match a product to your measurements before ordering it.

This enables you to get the best fitment possible and not settle for something subpar or even worse, something that doesn’t fit!

woman holding her sunglasses
Image Credit: StockSnap, Pixabay


Sunglasses that fit correctly can be the difference between a pair that you love and a pair that you never wear.

So, take your time, get your measurements, and track down a pair of sunglasses that has those measurements. You’ll get a perfect fit, so you can stay comfortable and do activity after activity with your sunglasses staying perfectly in place.

Featured Image Credit: Victoria Chudinova, Shutterstock

About the Author Robert Sparks

Robert’s obsession with all things optical started early in life, when his optician father would bring home prototypes for Robert to play with. Nowadays, Robert is dedicated to helping others find the right optics for their needs. His hobbies include astronomy, astrophysics, and model building. Originally from Newark, NJ, he resides in Santa Fe, New Mexico, where the nighttime skies are filled with glittering stars.