How to Measure Your Face to Find the Best-Fitting Glasses Online

Oh those nice glasses! You’re just itching to try them.

But they’re only sold online. How can you be sure they’ll fit right?

Getting glasses that properly fit your face is important for several reasons.

Appearance is one of them, as of course, you want the glasses to look good on you. But ill-fitting glasses can cause several problems, including blurry vision, headaches, eyestrain, dizziness, and more.

It used to be that you had to go to the optometrist or eye health store to purchase your glasses. But today, you have a lot more options, including many online-only glasses stores.

There are several advantages to shopping online, including convenience, access to several brands—including niche brands—and a larger inventory. You can also browse at your own leisure, without feeling pressured after an eye appointment. But to get glasses that fit properly, you have to know what size frame will work best.

An eye health technician probably helped you fit your glasses at the doctor’s office. When shopping online, you need to fill that role for yourself. Fortunately, it’s not hard to do.

Much like you know your shoe and clothes size, you can learn what your best glasses size is too!


Why Measuring Your Face is Important When Shopping for Glasses

How well your glasses look and feel on your face—and how well you see through them—depends on various elements, including the size and shape of the frames and the size and shape of your face.

If you’re trying on glasses in the store, you can intuitively tell whether they look and feel good. But when buying online, you need to rely on some key measurements.

Just like you would look for a size 8 shoe when shopping for shoes online, you’ll want to look for a frame that’s 130-134 millimetres wide, as an example, or that has temples (the “arms” of the glasses) that are 140 millimetres long.

Different glasses online stores will provide varying information on the sizes of their glasses. They may give you the specific measurements, or they may simply ask you to choose between small, medium, and large.

Understanding your unique face size and measurements will help improve the odds that you’ll get a pair of glasses that will work for you.


5 Measurements You Need to Understand to Buy Glasses Online

Before you start picking out frame styles and colours, familiar yourself with the following frame dimensions. Finding a close match between the frame you’re considering purchasing and your face is a good place to start when it comes to getting the best-fitting glasses online.

Note that it’s best to record your measurements in millimetres, as that’s the figure most commonly used when referring to the various dimensions of a frame.


Frame Width

This is often one of the first things you’ll notice about a pair of frames—how wide they are from side to side. The measurement is usually taken from endpiece to endpiece, or from hinge to hinge. The typical range is from 125 mm to 150 mm.

In general, the width of your frames should be close to the width of your face at the temples. You don’t want frames that are too wide for your face, as it’s important for your eyes to be centred within the lenses.

In a frame that’s too wide, you may not be looking through the centre of the lens, which could skew your vision.

A frame that is close to the same width as your face will also look best on you, creating a balanced appearance.


Find Your Best Frame Width

To find your face measurement for frame width, follow these steps:

  • Get a flexible measuring tape if you have one. If not, a ruler will do.
  • Stand in front of a mirror.
  • Hold the tape or ruler across your face and below your eyes.
  • Measure the distance between the left and right temples. You’re targeting the small bumps on the sides of your forehead. Keep the tape as level as you can.
  • Record the measurement in millimeters.

Man with ruler across his face measuring the distance between his temples

Then compare your measurement with the measurement of your frames. You can measure one of your old frames to get the idea. If your temple-to-temple width is 132 mm, then the best frame for you would be between 130-134 mm.

Small, medium, and large frames are typically categorized as follows:

  • Small: <129 mm
  • Medium: 130-139 mm
  • Large: >139 mm


Lens Width

Though the frame width probably won’t be listed anywhere on the frame, the next three measurements will be. Get out an old pair of glasses and look at the inside of the temple. On one of them, you’ll see a group of three numbers. They refer to the lens width, bridge width, and temple length, respectively. The numbers are usually written like this: 44 [] 22-145

We’ll start with lens width. This is the width of the lenses of your glasses at their widest point.


Find Your Best Lens Width

To calculate your lens width, follow these steps:

  • Get out a standard credit card and stand in front of a mirror.  
  • Hold the credit card under one eye, with the long edge aligned with the middle of your nose. In other words, hold it vertically so that you’re using the short edge to measure.
  • See how far the credit card extends under your eye. If the card’s edge goes past the outer edge of your eye, you will probably do best with smaller frames and narrower lens widths. If it ends right at the edge of your eye, a medium-size frame will probably be best. If it doesn’t reach the edge of your eye, go for larger frames with wider lenses.

How To Use A Credit Card To Measure Correct Lens Width

As a guideline:

  • Small lens width: 50 mm or less
  • Medium lens width: 51-54 mm
  • Large lens width: 55 mm or greater


Bridge Width

This measurement is the second number written on the temple, and it refers to the width of the space between the lenses.

It’s important because if you don’t get the right size, the frame may pinch your nose, causing pain, redness, and headaches, or it could slide down the bridge of your nose.

Because it refers to the placement of the lenses, it’s also important for clear vision.


Find Your Best Bridge Width

If you currently have a pair of glasses that fit well, it’s easiest to measure the bridge on them. If not, we’ll give you some other tips below.

  • Place your glasses on a flat surface with the lenses facing up. Make sure the temples are extended straight out behind the glasses—not bent.
  • Measure the small piece of the glasses that connects the two lenses. You’re not looking at the nose piece here, but the single piece that forms the bridge between the two lenses.
  • Make sure your ruler or tape is placed parallel to the top of the lenses.
  • Record the measurement in millimeters.

Illustration of where to measure glasses bridge

If your glasses have the measurements stamped on them, you can also look at the second number on the temple piece.

If you don’t have a pair of comfortable glasses to check, you can follow these steps:

  • Using a selfie taken of your profile, examine the bridge of your nose. This is where your glasses usually sit. For some people, the bridge is said to be low—at level with or slightly below your pupils, and is skinny in appearance. That correlates with a smaller bridge number. For others, the bridge is high (above the pupils) and wide. That means a higher bridge width. If you have a low bridge, look for frames with a bridge that dips below the brows. If you have a high bridge, look for a bridge at brow level.
  • Now look at a picture taken of the front of your face. Are your eyes closer together or wider apart? For those with close eyes, a thinner bridge will work better. Those with eyes wider apart will need a wider bridge.

Keep in mind that the thickness of the frame you’re looking at will affect how much bridge space you need. The thicker the frame, the wider the bridge will need to be.


Temple Length

The temple is the arm piece on your glasses. Sometimes called the temple arm, it extends from the front of the frame back behind your ear. This length is typically the last number listed of the three that are stamped on the temple.

If you have the right temple length, the glasses will fit comfortably over your ears. If they’re too small, they may pinch or hurt. Temples that are too long will cause your glasses to slide forward.


Find Your Best Temple Length

The best way to determine your temple length is to find a pair of glasses that fit well and check the last number stamped on the temple arm. If there is no number on yours, take these steps:

Illustration of How to Measure Temple Length of Glasses

  •  Measure the temple from the hinge on the main body of the glasses to the point where it starts to curve. 
  • Measure from the curve to the very tip of the temple arm.
  • Add the two measurements together.

If you don’t have a pair of glasses to check, you can place a measuring tape on your temple, about where the edge of the glasses would be, and extended it behind your ear and around to where the arm usually ends. This won’t be exact, but it will give you a general idea.

Temple length ranges from 120 to 150 mm, with the most common preset sizes being 135, 140, and 145 (for small, medium, and large, respectively).

When considering what length may be best for you, consider the frame width you discovered above. The wider the frame width, the longer the temples will need to be.


One More Thing to Measure for Buying Glasses Online

Once you have all the measurements above figured out, you’ll be in good shape for choosing a pair of well-fitting frames. There’s one more thing you should consider, though, and that’s your face shape.

Different types of frames look best on different face shapes, so you’ll want to have a general idea of what yours is.


Find Your Face Shape

To find your face shape, follow these steps:

  • Stand in front of a mirror. Pull your hair back or comb it back so you can focus on your face only.
  • Using a tube of lipstick or your finger dipped into a little water, trace the outline of your face from hairline to cheekbone to jaw on the mirror. (If you don’t want to actually trace it, just visualize it in your mind as you look at your face.)
  • Next, determine if your face shape is most like a circle, square, oval, or heart.

 For more clues, consider the following definition of each shape:

  • Circle shapes: You have a round face with full cheeks, and your forehead and jaw are about the same width.
  • Square shapes: You have a strong jawline, broad forehead and chin, and your forehead and jaw are about the same width.
  • Oval shapes: You have a narrow forehead and chin, and your cheekbones may be slightly wider. You have a subtly curved jawline.
  • Heart shapes: Your forehead is wider while your jawline is narrower. Your forehead tapers into your chin. You may also have prominent cheekbones.

If your face doesn’t fit perfectly into these categories, don’t worry. Most faces are a combination of one or more, but you can use the general shape of your face as a guideline when shopping for glasses.

Circle, oval, and heart shapes do best with boxier frames, whereas square shapes match best with oval and circular frames.



Measuring your face can provide you with the important information you need to find the perfect glasses online. Armed with these measurements, you’ll feel more confident that the frames you choose will fit your face well while giving you a stylish, balanced appearance.

Next time you go shopping, keep your individual sizes and shapes in mind. It’s not only about the look of the frames, but whether they will suit you!

Looking for more advice on choosing the perfect pair of glasses for you? Why not check out our selection of guides to choosing glasses for more help.

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