What Do the Numbers on Your Glasses Mean? Complete Shopping Guide

Ever picked up your glasses and noticed those tiny numbers on the inside? They might look like a mysterious code, but they're actually pretty important - especially when you're shopping for new frames.

If your glasses are old and tired, you want a new look, or you just need an extra pair, knowing what those little numbers mean will help you choose glasses that fit well without having to return them. You can do all this from home too! Keep reading to learn all about frame numbers—this could be the end of guesswork.

Where Can You Find Your Frame Size?

Take your glasses and look at the inner side of the temple (that's the arm that extends over your ear). You'll usually find a series of numbers there - they might be printed, etched, or stamped into the frame. Don't worry if you have to squint a bit; these numbers are often quite small!

Where to Find the Numbers

To find your glasses frame size, start by checking the inside of the left arm. If there's nothing there, try looking at the right arm or the part that sits on your nose. For metal frames, the size might even be on the nose pads.

What Is the Format?

The measurements typically appear in this format: 52-18-140

1. First number (52): Lens width

2. Second number (18): Bridge width

3. Third number (140): Temple length

All these measurements are in millimeters, making it easy to compare between different frames.

Can't See the Numbers?

If your frame numbers are worn off or hard to read, try these tips:

1. Use a magnifying glass or your phone's camera to zoom in

2. Look under bright lighting

3. Ask your local optician to measure your frames

4. Check your original glasses receipt or paperwork

5. Use a millimeter ruler to measure the parts yourself

Take a clear photo of these numbers when you get new glasses. This way, you'll always have your measurements handy when shopping online, even if the numbers wear off over time.

What You Need to Know About the Lens Width of Glasses

The lens width number on glasses is the measurement across the widest part of one lens. For example, if your glasses say "52" for lens width, that lens is 52 millimeters wide, which is a common and comfortable size for many people.

Lens Sizes: From Narrow to Wide Faces

Typically, lens widths range from 40mm to 62mm. For most adults, a frame width between 50mm and 54mm usually works well. If you have a narrower or smaller face, or prefer a more subtle glasses, look for sizes ranging from 40mm to 48mm. For those with wider faces or who want a statement look, sizes from 54mm to 62mm are ideal.

Lens Width Affects How Your Glasses Fit

Choosing the right lens width is key to ensuring your glasses not only fit comfortably within the natural width of your face but also do not stretch beyond your temples. It's this careful selection that keeps your eyes perfectly centered behind each lens, providing a balanced, proportional look that complements your overall features.

How to Tell If Your Glasses Fit Wrong

If your glasses don't fit quite right, the lens width might be off. Here are some signs that the lens width isn't perfect for you:1. If your glasses extend beyond the sides of your face, the lens width is likely too large.

2. When the frames are too wide, they can pinch the sides of your head, causing discomfort.

3. Look straight ahead. If your pupils aren't aligned with the center of each lens, the width may not be suited to your face.

4. If glasses slip down often, it could mean the overall width is too wide for your nose bridge.

5. Noticeable gaps between your temples and the frames suggest the lens width is too small.

If you're between sizes, it's usually better to go slightly smaller rather than larger, especially for daily wear glasses. The lens width works together with other measurements to create your perfect fit. While this number is important, it's just one part of finding frames that both look and feel great.

What You Need to Know About the Bridge Width of Glasses

When you look at those frame numbers, the middle number (like the "18" in 52-18-140) represents your bridge width. This measures the distance between your lenses across your nose, and it's crucial for how your glasses feel when you wear them.

A well-fitted bridge keeps your glasses centered on your face and prevents them from sliding down your nose. Most adults have bridge measurements between 14-24 millimeters, with 16-18mm being the most common range. Your ideal bridge width depends largely on your nose structure and where you prefer your glasses to sit.

How to Find Your Perfect Bridge Width

● For Higher Nose Bridges: Choose wider measurements (18-21mm) to ensure your frames rest comfortably without pinching. These measurements give your nose breathing room while keeping your glasses stable.

● For Lower or Flatter Nose Bridges: Look for smaller measurements (14-17mm) to prevent your glasses from sliding. You might also want to consider frames with adjustable nose pads for extra stability.

● For Average Nose Bridges: Stick to standard measurements (16-18mm) which typically work well for most face shapes and provide balanced comfort.

Signs Your Bridge Width Isn't Right

● Too Wide: Your glasses constantly slide down your nose, or there's a visible gap between the bridge and your nose

● Too Narrow: You notice red marks or feel pinching on the sides of your nose

● Uneven Sit: Your glasses tilt to one side or feel unbalanced on your face

If your current glasses stay in place without sliding and don't leave uncomfortable marks, use that bridge measurement as your starting point when shopping glasses online. It's okay to vary by 1-2mm, but bigger changes might affect your comfort.

What You Need to Know About the Temple Length of Glasses

The last number in your frame measurements (like the "140" in 52-18-140) is your temple length - it's the measurement of those long arms that extend from your frames to behind your ears. Getting this length right is crucial for both comfort and keeping your glasses properly positioned on your face.

How to Find Your Ideal Temple Length

The most common temple lengths range from 135 to 150 millimeters, with 140mm being the most standard size. The length you need depends on the distance from your temple to the back of your ear, as well as how you like your glasses to fit.

● Short Temples (135mm): These work well for smaller faces or if you have a shorter distance from temple to ear. They're also good for children's frames or petite adult sizes.

● Standard Temples (140-145mm): This range fits most adults comfortably. The temples should reach just past your ears without extending too far beyond them.

● Long Temples (150mm+): Better for larger faces or if you have a longer distance from temple to ear. These might also be preferred if you want your glasses to fit more loosely.

Signs Your Temple Length Isn't Right

● Too Long: The temples extend far beyond your ears, or the glasses feel loose and unstable

● Too Short: You feel pressure behind your ears, or the temples don't reach far enough to secure your glasses

● Wrong Angle: Your glasses sit too high or low on your face because the temples can't rest properly

How to Test Temple Fit

Check these points for proper temple fit:

● The curve should start just above your ear

● The temple should follow your ear's natural curve without pressure

● You shouldn't feel the temple tips poking behind your ears

● Your glasses should stay in place when you move your head

If you've found a comfortable pair of glasses, always check their temple length before buying new frames online. While you can vary slightly from your current measurement, dramatic changes might affect how well your glasses stay in place.

How Frame Measurements Work Together: Creating Your Perfect Fit

How to Calculate Total Frame Width

Your total frame width is more than just the lens width. Here's a simple formula to understand the full picture:

Total Width = (Lens Width × 2) + Bridge Width

For example: If your measurements are 52-18-140, your total frame width would be 52 + 52 + 18 = 122mm

How Do Frame Measurements Work Together?

What Size Frames Match Your Face Shape?

What Should You Do If Your Glasses Don't Fit Well?

● If frames slide: Check if you need a smaller bridge width or longer temples

● If frames pinch: Look for a wider bridge or different temple curve

● If frames look unbalanced: Adjust the proportion between lens width and bridge

● If frames feel heavy: Consider how the measurements distribute the weight