How To Measure Frame Width For Glasses - Choose What Fits Your Face The Most!

How To Measure Frame Width For Glasses - Choose What Fits Your Face The Most!

Back to blog

Are you looking for new glasses that fit the shape and size of your face, or do you already have a pair of glasses but are unsure if their size is suitable for you? 

In this article, we will guide you carefully on how to measure frame width for glasses correctly and what you can do to pick the best pair of eyewear for yourself! The blog will talk about all the small factors like frame width, the bridge, lens height, and other things to determine a good glass size. Scroll down!

how to measure frame width for glasses

Measure the Frame Width - The Four Main Number of Your Glasses

Some of you might wonder why we should measure the frame width while the spectacles seem to already do a good job for us. 

The reason is that having spectacles that fit your face well enough does not also mean they are the best choice for you. In fact, you need to do a further job by first looking at certain numbers on the eyewear.

Here is the basic method to read these numbers:

  • The first number - Lens Width

Normally, the number of it is somewhere around 40 to 60 millimeters written after a square symbol. 

  • The second number - Bridge Width

It is around 14 and 24 millimeters. 

  • The third number - Temple Length

This number normally ends with 0 or 5, and it is somewhere around 120 to 150 millimeters. 

  • The fourth (normally the last) number - Lens Height 

The height of your lenses can be around 32 to 38 millimeters. 

“Why should I look at these numbers so carefully when the spectacles seem to fit me perfectly?”- you might ask.

The main reason for doing this is to pick the best eyewear for your face ratio that will increase the effectiveness of the spectacles you wear, especially when wearing this accessory to deal with certain eye conditions. 

If a person with a big face wears a small pair of eyewear, there might be some problems accrue when they look further up or further down. 

Measure The Lens Width

Lens width is the width of your lens (only one lens, not two) counted from one side to the other and horizontally. The number is counted in millimeters, and it can be somewhere between 40 to 60 millimeters. Sometimes, people also call lens width “eye size.”

While measuring the lens width of your spectacles, it is crucial to keep in mind that you only need to measure the lenses (no need for measuring the spectacles’ frames). You can estimate all the numbers of your eyeglasses by using a metric tape measure. 

Measure The Bridge

To estimate your spectacles’ bridge, gauge the distance between the two lenses horizontally and start with one innermost spot of each lens. 

Keeping the eyewear on your face will be easier when you pick the pair with the right bridge. You can also feel more comfortable in them as the bridge will stay put on your nose. 

If the bridge is too short, you would feel a little bit painful while wearing it. Otherwise, the eyewear might cause difficulty in seeing. 

Measure The Temple Arms

The temple arm length is the length of your spectacles’ arm piece. This part of the glass will stay put on your face. Its length can be estimated from where it connects with the frame and to the arms bend. In other words, its length is counted from the starting to the ending point of the arm. 

Kids and adults with different head and face measurements require different eyewear sizes. The size of the temple arms can be as short as 120 mm or as long as 150mm. 

However, you would be more likely to find spectacles that are around 135 to 150mm. Most template arm numbers will fall into certain standard numbers, like 135 mm, 149 mm, 145 mm, and 150 mm. 

What happens when you wear glass with a short temple arm is that you will feel like your ears are hurt, and you might have a headache after a long time of use. On the contrary, eyewear with too-long temple arms might drop off the point it is supposed to stay. 

Measure The Lens Height

If lens width is gauged horizontally, the lens height is counted vertically from the top to the bottom point of each lens. The lens height can vary depending on the style and purpose of the eyeglasses, as long as it meets certain standards. 

For progressive prescriptions and bifocals, the lens height needs to be longer than 30 mm. Typically, you will find eyewear with lens height around 32 to 38 mm.  

Most of the time, you do not need to care much about the lens height if you are not searching for bifocals or progressive prescriptions. Another thing to keep in mind is that the frame’s button should not rub your cheeks. 

Other Things To Keep in Mind

If The Glasses Are too Big, They Will Slip Down Our Face

Have you seen someone who has a big pair of spectacles slipping down their face? It is what happens if you pick eyewear with frame widths that are too big for you!

Wrong Size of Frame Width Can Cause Vision Troubles

When the frame width is unfit, you might encounter some vision trouble. For example, when the bridge is too long for you, you might have issues seeing things as the area of your caruncle (the inner corner of the eyes) might not be 100% covered with your spectacles. 

Pick the Right Glass Size Based on Your Face

By measuring the distance of your cheeks from the furthest point of each side, you can determine whether your face size is tiny, medium, or large. After you measure the distance of your two cheeks, write down the number and start checking now. 

  • 125 to 129 millimeter: Tiny face size
  • 130 to 134 millimeter: Medium face size
  • 135 to 139 millimeter: Larger face size (also called bigger-than-average or larger-than-average size)

Use Virtual Try-On Sites When You Want to Buy Glasses Online

If you get yourself a pair of eyewear, do not rush and pick the one you need without measuring it. In case you are not in the store to try different sizes of spectacles to check if they fit well and feel right on your face, you can estimate it via online websites that have virtual try-on choices.

This smart technology allows you to virtually try on any pair of eyewear to determine which ones fit you the most. 

What If Your Glasses Already Have Measurements?

When your spectacles already have measurements and are not too right for you, you can change them a little bit by doing the following things: 

When the eyewear is too wide, bend the frame super gently and try it until you feel more right. Remember that you should do this super gently and never use heat!

If there is any factor you cannot change by yourself, it is advisable to go to some optometrist office and ask for help. They might change certain things about your spectacles that make them fit your face more without getting you to buy a whole new one.


With specific numbers of the spectacles frame width and other pieces of information in this article, we hope you now know how to measure frame width for glasses correctly! 

Remember that the right pair of eyewear will make your vision clever, so please take some time to read the number and pick a suitable one for you. If you cannot come to the store, you can try them virtually before buying.