Glasses that don’t fit right can cause headaches and irritation.

Have the backs of your ears ever been sore while wearing glasses? That’s probably because you have the wrong size. For the best vision possible, you should wear glasses that perfectly fit your face.

Plus, well-tailored specs look great! With the right pair, you’ll be comfortable and stylish.

So how do you know what size glasses to wear? It depends on a few simple factors you can learn about at home.

What Size Glasses Do I Need for my Face?

First, your glasses shouldn’t cause pain. Adjusting to new prescription lenses may lead to headaches for a short time, but prolonged irritation can be a sign of poorly fitting frames. There shouldn’t be pain around your ears either. You need better glasses if you notice small indentations on the sides of your head or if your ears hurt.

Glasses should also align properly with your face.

• Your glasses are too wide if the frame extends beyond your temples.
• Your frames generally shouldn’t reach above your eyebrows. It’s ok if some larger styles do.
• Your glasses shouldn’t touch your cheeks. It could cause irritation.
• Your glasses shouldn't feel tight on your nose.

If you already own glasses that meet those standards — perfect! The size is ideal.

Many frames have millimeter measurements printed on the arms. You can use those numbers to buy glasses that fit the same as your current pair. Check for a sequence of three numbers, like 52 - 19 - 140.

The first number is lens diameter, the second is bridge width, and the third is arm length.

At 39DollarGlasses, we provide the measurements of each frame. Choose frames with measurements matching your current pair for the best fit.

If your glasses don’t list measurements, you can still use them to find the perfect fit. You’ll just need a ruler or measuring tape with millimeter marks. Measure the bridge width first. Next, measure the arm length, lens width, and lens height. (If your ruler measures in inches, multiply the number by 25.4 to convert it to millimeters.)

If you don’t have glasses, you should measure your face instead. You’ll need a ruler and a mirror, or someone to measure for you.

Place the ruler at the bridge of your nose, in line with your temples, and measure the distance.

Choose glasses that have the same total width as your face.

As a general rule, your frames can vary +/- 3mm from your face measurement. Any more and they might not fit. We list the width of all our frames so you can pick glasses based on your personal measurements.

Face Measurement to Glasses Size

Now that you have your measurements, let’s choose the best glasses for your face. For most people, perfectly sized frames match their face shape. If you have a wider face shape, glasses over 139 mm wide will probably fit well. Smaller faces usually pair with frames less than 129 mm wide.

Other factors can play a role too. Have you ever heard of diamond, square, or oval faces? Those terms describe the general appearance of different facial structures. Your glasses’ size should account for those features. For example, square features include broad cheekbones — making wider glasses fit better.

You can identify your face shape with our helpful chart.

For most people, glasses that add contrast look great. Try wearing broad rectangle glasses if you have a wide, round face. Or choose rounded frames for a square face with medium width.

Order Perfectly Sized Glasses from 39DollarGlasses

No matter the style, your glasses should always fit comfortably. Make sure your frames are the right size by shopping at 39DollarGlasses.

As a company founded by eye doctors, healthy vision is our top priority. That’s why we list comprehensive measurements for each style, giving you the power to wear glasses ideally tailored to your face.

Plus, we offer free return shipping. If you mix up your measurements, we’ll help you get a new pair that fits perfectly.

Discover the best glasses today with 39DollarGlasses!