Ever dealt with sunglasses sliding down your nose during an important meeting, or ordered a pair online only to find they look completely wrong? For busy professionals in startups, mega businesses, or trading, details like sunglass fit impact comfort, focus, and image. Understanding how to measure sunglasses size is key to avoiding these issues.
This guide demystifies sunglass measurements, helping you find a perfect-fitting pair that boosts confidence and ensures all-day comfort. Let’s ditch the ill-fitting frames and find sunglasses that feel custom-made.
Understand the Numbers on Your Sunglasses
Most high-quality sunglasses carry a hidden message – a sequence of numbers typically etched discreetly on the inside of one of the temple arms (the parts that go over your ears). Think of these numbers as the secret formula for your perfect fit. They usually appear in a format like “52-18-140,” and the measurements are universally given in millimeters (mm). Let’s delve into what these critical digits, along with a couple of other important dimensions, truly signify.
The first number in this sequence, for instance, the 52 in 52-18-140, represents the Lens Width, sometimes called “eye size”. This measures the horizontal width of each lens at its widest point. It’s crucial to note this measurement refers only to the lens itself, not the surrounding frame. Why is this important? The lens width significantly influences how your eyes appear centered within the frames.
If the lenses are too wide for your face, your eyes might seem unnaturally close together; conversely, if they’re too narrow, your eyes can look wide-set. Getting this right is fundamental for both visual comfort and achieving a balanced, proportionate look. Knowing how to measure lens width for sunglasses is therefore a cornerstone of finding the right pair. Lens widths typically range from 40mm to 60mm.
Next in the sequence is the Bridge Width, represented by the 18 in our 52-18-140 example. This number indicates the distance between the two lenses, specifically measuring the part of the frame designed to rest comfortably on the bridge of your nose. This measurement is absolutely critical for comfort.
A bridge that’s too narrow will pinch uncomfortably, while one that’s too wide will lead to the dreaded sunglass slide – a major distraction when you need to maintain focus during a presentation or analyze market data. Some eyewear experts even consider the bridge width the single most vital measurement for ensuring an accurate and stable fit. Typical bridge widths fall between 14mm and 24mm.
Finally, the third number, the 140 in 52-18-140, denotes the Temple Length or arm length. This is the total length of the sunglass arm, measured from the hinge where it connects to the main frame, all the way back to the tip that tucks securely behind your ear. Proper temple length ensures the sunglasses stay put. Arms that are too short won’t reach comfortably or securely behind your ears, causing the frames to slip forward.
If they’re excessively long, they can feel awkward, push the glasses out of position, or interfere with hats or even your hairstyle. You’re looking for that perfect, gentle grip that provides security without pressure for all-day wear. Common temple lengths range from 120mm to 150mm , though longer options exist.
Other Dimensions Worth Noting
While those three numbers form the standard measurement code, a couple of other dimensions play a significant role in the overall fit and function of your sunglasses:
Lens Height: This is the vertical measurement of the lens at its tallest point within the frame. You won’t usually find this number printed on the frame itself, but it’s commonly listed in the product details on retailer websites. Lens height matters for a couple of key reasons.
Firstly, if you require progressive or bifocal lenses, there’s often a minimum height needed (typically around 30mm) to accommodate the different visual zones. Secondly, for individuals with high cheekbones or smaller facial structures, choosing a frame with an appropriate lens height can prevent the bottom edge of the sunglasses from resting uncomfortably on the cheeks. Lens heights often range from 32mm to 38mm.
Total Frame Width: This measurement captures the overall horizontal width of the entire sunglass front, measured from the absolute outermost edge on one side to the outermost edge on the other. This includes any parts of the frame, hinges, or design elements that might protrude. Learning how to measure frame size of sunglasses in this holistic way is vital for judging proportion.
Unlike the other core measurements, this one isn’t typically printed on the frame. Why is it important? Total frame width is the key determinant of whether the sunglasses look proportionally balanced on your face.
The general guideline is that the frames should be just slightly wider than your face, ideally leaving no more than a finger’s width of gap between the temple arm and the side of your head. Your eyes should also appear well-centered within the width of the lenses. You’ll usually need to measure this yourself on an existing pair or find the specification listed online.
Method 1: Leverage Your Existing Favorite Pair
Do you already own a pair of sunglasses whose fit you absolutely adore? If so, you possess the easiest key to unlocking your ideal measurements.
First, Read the Markings. Simply pick up your well-fitting sunglasses and examine the inside of either temple arm. Occasionally, the numbers might be printed on the bridge instead. Look for that sequence of three numbers (e.g., 52-18-140 or sometimes shown as 52 □ 18 140). These represent your lens width, bridge width, and temple length, respectively. Make a note of these numbers – they are your benchmark.
However, sometimes those tiny numbers can wear away over time. Don’t worry! You can perform a Manual Measurement yourself. All you need is a ruler with millimeter markings – a plastic one is often recommended to avoid accidentally scratching your lenses – or a soft measuring tape.
- To measure Lens Width, place the ruler horizontally across one lens at its absolute widest point, measuring only the lens, not the frame.
- For Bridge Width, measure the distance between the inner edges of the two lenses, right where the frame is designed to sit on your nose.
- Measuring Temple Length involves placing the ruler at the hinge screw and measuring straight along the arm to its very tip. Some guides suggest measuring in two parts if there’s a distinct curve – hinge to curve, then curve to tip – and adding them together.
- To find the Total Frame Width, lay your sunglasses flat and measure horizontally across the entire front at the widest point, making sure to include any protruding frame parts or hinges.
- Finally, for Lens Height, measure vertically at the tallest part of one lens, again excluding the frame.
Method 2: Measure Your Face – Creating Your Personal Blueprint
What if you don’t have a reference pair, or you’re venturing into the world of premium sunglasses for the first time? Fear not! You can get an excellent estimate of your required size by directly measuring your face. This is where you learn how to measure face for sunglasses.
A key starting point is determining your Head/Face Width (Temple-to-Temple). This measurement is invaluable for gauging the appropriate overall frame width and is a crucial part of understanding how to measure head for sunglasses. You’ll need a straight ruler (a flexible tape measure can curve and lead to inaccuracies here ) and a mirror. Stand facing the mirror and hold the ruler horizontally across your face, positioned just below eye level.
Measure the distance straight across from your left temple to your right temple – the temples are the flat areas on the sides of your head, between the outer corners of your eyes and your ears. This temple-to-temple measurement in millimeters or centimeters/inches can often be directly correlated with general size categories using charts provided by retailers.
Table 1: Example Face Width to Sunglass Size Guide
| Face Width (Temple-to-Temple) | Typical Sunglass Size Category |
| Less than 129mm (~5.1 inches) | Small / Narrow |
| 130mm – 139mm (~5.1 – 5.5 inches) | Medium / Average |
| 140mm and wider (~5.5 inches +) | Large / Wide |
(Note: Always refer to the specific brand’s sizing chart, as categories can vary.)
For a quick, rough estimate, you can try the popular Credit Card Trick. While it lacks the precision of a ruler, it uses a readily available item and provides a surprisingly useful starting point. There are a couple of variations:
- Revant Optics’ Method : Stand before a mirror. Place a standard credit card vertically on the bridge of your nose, also under your eyebrow, forming an “L” shape. Now, observe where the outer edge of the card falls relative to the outer edge of your eye. If the card extends beyond your eye, you likely need a Small size. If it lines up with your eye’s edge, Medium is probable. If the card’s edge falls inside the edge of your eye, lean towards a Large size.
- Warby Parker’s Method : Hold the short edge of the credit card (about 54mm) under one eye, with the long edge aligned vertically down the middle of your nose. If the card’s outer edge goes past the outer corner of your eye, you might look for narrower lens widths. If it ends at the corner of your eye, a medium size frame might be suitable.
Remember, this is a clever estimation tool, perfect for getting a general sense of size before refining with more exact measurements.
Don’t forget to Assess Your Nose Bridge. Your nose shape significantly impacts how glasses sit. Take a moment to look in the mirror, perhaps even taking a side-profile selfie. Is your bridge wide or narrow? Does it start high on your face (above your pupils) or low (level with or below your pupils)? Generally, if your bridge is narrow or sits low, you’ll be more comfortable with a smaller bridge width number (e.g., 16-18mm).
If it’s wide or starts high, a larger bridge number (e.g., 19-21mm) will likely provide a better fit. If finding a comfortable bridge fit has always been a challenge, consider frames with adjustable nose pads (often found on metal styles) or look for designs specifically labeled as “Low Bridge Fit” or “Asian Fit,” which are crafted to accommodate lower nose bridges and higher cheekbones.
Translate Measurements into the Perfect Fit
You’ve gathered your numbers using the methods for how to measure sunglasses size – now what? The goal is to find sunglasses that are not just stylish but also supremely comfortable and provide excellent protection.
Here are some key principles for a great fit:
- Frame Width: As mentioned, the total width should be just slightly wider than your face, ensuring your eyes appear centered within the lenses.
- Bridge Fit: The frame should rest comfortably on your nose without pinching or putting undue pressure on one spot. Critically, it shouldn’t constantly slide down.
- Temple Comfort: The arms should feel secure along the sides of your head without digging in. The curve should rest snugly and comfortably over your ears.
Many retailers provide helpful sizing charts that translate specific measurements into size categories like Small, Medium, or Large. These charts can be based on lens width, bridge width, temple length, or even your overall face width.
Table 2: Example Lens Width Sizing
| Lens Width (mm) | Typical Size Category |
| 50mm and under | Small / Narrow |
| 51mm – 54mm | Medium / Average |
| 55mm and wider | Large / Wide |
Table 3: Example Bridge Width Sizing
| Bridge Width (mm) | Typical Size Category |
| 14mm – 17mm | Small / Narrow |
| 18mm – 19mm | Medium / Average |
| 20mm – 23mm+ | Large / Wide |
Table 4: Example Temple Length Sizing
| Temple Length (mm) | Typical Size Category |
| 135mm – 140mm | Small / Medium |
| 145mm | Medium / Large |
| 150mm and above | Large / Extra Large |
(Important Caveat: Size classifications like “Small,” “Medium,” and “Large” can differ between brands. Relying on your specific millimeter measurements provides a more universal reference point when comparing styles across different manufacturers.)
Pro Tips for the Astute Sunglass Shopper (That Means You!)
For professionals operating in the high-stakes environments of startups, global corporations, and financial trading, your eyewear is a functional tool and a statement piece.
- Enhance Your Presence: Well-fitting, high-quality sunglasses project an image of meticulousness and polish, whether you’re meeting clients outdoors or simply commuting.
- Prioritize All-Day Comfort: Long days involving travel, outdoor meetings, or site visits demand comfortable eyewear. The right fit eliminates distractions and allows you to focus on the task at hand.
- Navigate Online Shopping with Precision: Knowing your measurements empowers you to confidently browse online collections, significantly increasing the likelihood of finding the perfect fit on the first try and saving valuable time.
- Consider Style and Face Shape: While measurements provide the foundation for fit, don’t forget to choose frame shapes (like aviator, wayfarer, rectangular, or round) that complement your facial features and align with your professional image.
- Insist on UV Protection: This is non-negotiable for eye health. Ensure any pair you consider offers 100% UV protection to safeguard your vision.
- Leverage Expert Advice: If you’re exploring options from a quality provider like Julong Eyewear, utilize customer service resources. They can often offer tailored advice based on your measurements and needs.
Your Vision, Perfectly Framed
Mastering how to measure sunglasses size is more than just learning numbers; it’s about taking control of your comfort, protection, and style. By understanding the significance of lens width, bridge width, and temple length, and knowing how to measure your own features, you’re no longer guessing. You’re making informed decisions.
Armed with this knowledge, you can confidently select your next pair of sunglasses. Whether you’re closing a major deal under the sun, leading your team at an outdoor retreat, or strategizing your next market move, do it with the clarity, comfort, and confidence that comes from a perfect fit. Your ideal sunglasses are waiting.
