Lensology’s Glasses Measurement Guide

Jan 4, 2024

Believe it or not, glasses don’t simply come in small, medium or large. Nor is there a one-size-fits-all solution. Glasses should be customised to the wearer; it’s what makes them unique, as well as being practical and comfortable for those wearing them.

Previously, you had to book in with your local optician and pop on those Inspector Gadget-type frames to figure out the perfect fit for your frames. Yes, this is still an option and recommended if you’re experiencing any concerns or discomfort with your eye health. However, you can easily figure out your glasses size in the comfort of your home. So, when you’re ordering a brand new pair of glasses or designer sunglasses, you know they’ll frame your face perfectly.


Why the correct frame size is important

Yes, you can purchase glasses frames or sunglasses straight off the shelf, but realistically, how long do they last? Are they a little tight on your temple? Or have they stretched and now keep sliding off? Whether you require glasses for long or short-sightedness or you’re investing in a branded pair of frames, you want to make sure they match your exact measurements. Not only does this make your frame bespoke to you, but it also ensures they’re comfortable to wear, reduce eye strain or tension, and sit correctly on your nose for clear and consistent vision.


How to find your glasses measurements

There are three ways to figure out your precise frame measurements:

Look at your existing frames

If you’re a glasses wearer and happy with the fit of your existing frames, we recommend sticking with these measurements. You should spot three sets of numbers inside the arm or bridge of your frame, such as 54 ▯ 17 140. The number to the left of the rectangle (54) equals your lens width. The number to the right of the rectangle (17) equals the bridge width, and the final number (140) equals the arm length. You can pop these measurements in when ordering your glasses frames online.



Use a glasses sizing guide

If you’re new to glasses or don’t like the fit of your existing frames, you can check your face measurements with a glasses size guide. You have to note down five key measurements, all measured in millimetres: the frame width, lens height, lens width, bridge width and arm length. We’ve included our sizing guide below to help you log the exact sizing for your glasses.


See Your Optician

If you’re unsure how to get the right measurements or experiencing any pain or visual discomfort, we recommend booking an appointment with your optician. They can check the current condition of your eyes and provide you with your frame measurements, which you can use to order your frames in-store or online.


How to measure for a pair of glasses at home

As we mentioned earlier, your glasses frame size guide consists of five key measurements. Figure these out, and you’re good to go!

Glasses size guide breakdown

Frame Width – The easiest way to achieve this measurement is by taking a ruler and standing in front of a mirror. Place the ruler horizontally below your eyes and measure the distance between your temples in millimetres. This helps determine the size of your face and, therefore, the best type of frame.

Lens Width – Also referred to as the lens diameter, this focuses on the size of your lens and can be influenced by the style and shape of your frames, as well as your prescription requirements. The lens width is measured from the bridge of your nose to your temple, taking two separate measurements for left and right, although they are often the same.

Lens Height – Similarly to the lens width, this can be determined by the size and shape of your chosen frames. But as a note, your lens shouldn’t reach any higher than your eyebrows, and they shouldn’t rest on or touch your cheeks – after a while, this just becomes irritating! Take your measurements just below your eyebrows and just above your cheeks for the right lens height.

Bridge Width – This refers to the distance across your nose between the two lenses, ranging from 14-24mms. This is an important measurement and needs to be accurate for a comfortable fit; if it is too tight, your frames will pinch your nose and cause discomfort. Too big and your glasses will continuously slip off. Again, use a ruler and mirror to measure your nose bridge in millimetres and be mindful of the material and style of your frames, as varying thicknesses and nose pads can make a difference.

Arm Length – Arm lengths can vary from 120-150mm. Again, this needs to be a comfortable fit so the arm hooks neatly behind your ear: too long, and your glasses will be unstable. Too short, and they’ll rub, causing pain and tension. Use a ruler to measure from the edge of your eyebrow to just behind your ear.


Choosing the right glasses size for your face shape

From oval and heart to square and rectangular, we all have different face shapes. Thankfully, there are numerous styles of glasses to suit our taste and fit beautifully on our faces. You might already have a look in mind, but for those unsure which glasses will frame their face best, here are our suggestions:

Small and narrow faces – look for smaller frames less than 129 wide.

Medium and oval faces – opt for frames between 130 – 139mm wide.

Large and round faces – frame widths of 139mm or more will offer a stylish fit.

No matter the shape, size or style of glasses you go for, there are some essential points worth repeating: the top of the frame shouldn’t sit any higher than your eyebrows, and the bottom should sit just above your cheeks. Finally, the width of your frames should be no wider than the width of your face.


You’ve found your glasses size; now what?

Great! Now, you can shop online for those must-have glasses frames, knowing they’ll fit like a dream. Once you’ve found your frames but want to enhance them, that’s where Lensology can help you out. Whether you need a prescription lens or want to protect your eyes with blue light filters, UV protection or polarised lenses, our in-house technicians can fit bespoke lenses directly into your perfectly sized frames. View our lenses to see what’s available to you.


Ready to order your FREE pack?

We provide a free postal pack that is delivered straight to your door, inclusive of a free return postage box for your frames. You’ll just need to provide a few simple details and then we can get it over to you ASAP!