A Comprehensive Guide to Understanding Sunglasses Size

The world of sunglasses has become very specialized. You can get polarized, gradient, mirrored, and even translucent sunglasses. All these different shades come in a massive range of shapes and sizes—and that’s where it gets complicated!

The best thing to do is take the time to understand how your sunglasses size works before buying new shades.

What Are Sunglasses Size?

sunglasses size

Sunglasses size is the measurement of the width of a pair of sunglasses. It is measured in millimeters and is taken across the lens. The measurements are taken from one side to the other, not across its length. The four significant measurements defining the sunglasses size include:

  • Lens Width - This refers to how wide or narrow your lenses will be on your frames.
  • Temple Size - It determines how long your temples (arms) will be on your frame.
  • Bridge Size - The bridge connects either side of your nose and holds most of the weight from both lenses.
  • Lens Height - The height from the bottom lens line to the top lens line. The lens height will make or break your sunglasses. A lens that is too low will sit on top of your nose, which isn’t a good look for most people. The right height will allow you to see comfortably without the lenses resting on your nose.

Kindly refer to this detailed guide to determine your sunglasses size correctly.

Why Does Sunglasses Size Matter?

sunglasses size

One of the most important considerations when purchasing sunglasses is your size. The right pair can brighten any day, but if they're too big or small, they'll be unable to provide you with their intended benefits.

Sunglasses that fit well will be comfortable, won't slip or fall off, and are easy to see through. They'll also prevent glare from harming your eyesight and keep the sun out of your field of vision during outdoor activities such as cycling or fishing.

On the other hand, wearing glasses that are too small can cause headaches due to tightness around our temples or eye sockets—not very pleasant!

Alternatively, sunglasses that are too big will slip off your face easily, depriving you of the necessary coverage.

What Determines Sunglasses Size?

The first thing you need to know about sunglass sizes is that it depends on your face size, face shape, and the shape of the lenses you require. Five sunglasses sizes exist: extra narrow, narrow, medium, comprehensive, and extra wide. Each one of these has its distinct measurements depending on the above factors.

The next thing you need to know is that there are two different ways to determine your personal sunglasses size; one method is based on your face measurement, while another is based on some other physical attributes such as eye width or bridge width.

Extra Narrow: 126 - 129 mm

This is the smallest of all sunglasses sizes, and it's a snug fit. The frames are tall and narrow, and they'll sit on your face close to your eyes. Some people love this because it means their sunglasses don't slip down their noses when moving.

But others find that the frames pinch their ears or cheeks too much. These glasses are best for people with small faces or those whose face shapes make it difficult to carry oversized sunglasses.

Narrow: 130 - 133 mm

Narrow sunglasses are the most common sunglasses size, and they are suitable for people with narrow faces. If you have a thin, long face shape, this sunglasses size will look best on you.

People with broad faces should avoid wearing this style because it can make their head look even wider than it already is. On the other hand, people who have short or round faces should try to find a different style that fits better with their facial features, like the aviator style.

Medium: 134 - 137 mm

The perfect sunglasses size for most people. It's best for anyone who wants to maximize their vision and comfort. This sunglasses size works well with almost all face shapes, including oval and round.

The medium is a great place to start if you're looking for sunglasses that will fit perfectly without making your head look too small or large.

Wide: 138 -141 mm

Wide sunglasses are suitable for people with wider faces. They are also a good choice for those who want more sun coverage or a more sporty look.

If you have large eyes, you can use wide glasses to draw attention away from them and make your face appear smaller.

Extra Wide: >= 142 mm

This is the widest sunglasses size available and can be too big for most people. However, these might be the ones for you if you have an exceptionally large face.

Sunglasses with extra-wide frames usually come in styles where the lenses are farther apart. And because of this design quirk, they're not recommended for sports or other activities where it's essential to see clearly (think: biking).

They may also not work well if your face is petite; they tend to make small faces look even smaller by comparison.

However, if your features are more masculine or angular in shape—think a square jawline—they can help balance those features while making them seem more proportional overall.

Note: The sunglasses size chart differs from brand to brand. It’s thus essential to understand which face size falls into which category before making a purchase.

Sunglasses Size Based on Nationality

You can also choose sunglasses size based on the nationality of the wearer. Here’s how:

  • American: American people are the biggest consumers of eyewear in the world, so most brands offer them in bigger sunglasses sizes for maximum comfort and style. The average frame size for an American is 17-18 mm wide, with some models reaching as high as 19 mm or even 20 mm+.
  • Asian: Asians are generally more slender than Americans, which means they look better when wearing smaller frames (13-14 mm). If you're an Asian person looking for a pair of sunglasses, buy smaller sunglasses size. 
  • European: Europeans have medium-sized faces and heads compared to other ethnicities; therefore, they often require narrower glasses (12-13mm). You may find that if you're trying out different styles in this range, one will fit perfectly. South American: People from South America tend to have big heads relative to their bodies! So if you want something sleek & stylish, then opt for larger plastic frames without any metal parts.


I hope this article has helped you understand the different sunglasses sizes and some ideas for your next pair. The most important thing to remember is that everyone has a different face shape, so there is no one-size-fits-all style. That's why it's essential to try several different styles before making your choice!