Sunglasses Size Guide: Get Frame Width Right
TL;DR: Getting sunglasses size right comes down to matching frame width to your face width, and checking the three numbers stamped inside the temple arm: lens width, bridge width, and temple length. A frame that's too wide slides down your nose and looks oversized. Too narrow, and it pinches at the temples and looks small on your face. This guide covers how to read those size numbers, how to measure your own face in under two minutes, and what to look for when a size chart isn't available. Cali Life Co. sunglasses are handcrafted in standard adult sizing across bamboo, walnut, and oak frames, so once you know your numbers, the fit carries over from pair to pair.
Most people buy sunglasses by eye and hope for the best. It works often enough that nobody bothers to learn the actual sizing system, until a pair slides down their nose on a hot day or pinches after twenty minutes. Here's the system, in full.
How sunglasses sizing actually works
Every pair of sunglasses is built around three measurements, and almost every pair has them stamped in tiny numbers on the inside of one temple arm. Once you know your own numbers, you can check any frame against them before you buy, no fitting room required.
How to read the number stamped on your temple
The stamp usually reads as three numbers separated by a square or a dash, something like 52-18-140.
| Position | What it measures | Typical adult range | |---|---|---| | First number | Lens width in millimeters | 44 to 62mm | | Second number | Bridge width, the gap over your nose, in millimeters | 14 to 24mm | | Third number | Temple arm length in millimeters | 120 to 150mm |
Add the lens width and bridge width together and you get a rough sense of total frame width across the front. That single combined number is the one that decides whether a frame reads as right-sized, oversized, or too small on your face.
How to measure your own face in two minutes
1. Stand in front of a mirror with a soft tape measure or a ruler. 2. Measure straight across your face at its widest point, usually temple to temple just above the ears. 3. Convert to millimeters if your tape measure is in inches: multiply inches by 25.4. 4. That number is your target total frame width. A well-fitted frame usually lands within a few millimeters of it, not far under or wildly over.
Face width and frame width, side by side
| Face width | Recommended total frame width | |---|---| | Narrower (under 5.5 inches across) | Roughly 125 to 135mm | | Average (5.5 to 5.75 inches across) | Roughly 135 to 142mm | | Wider (over 5.75 inches across) | Roughly 142mm and up |
These are starting points, not hard rules. Frame shape shifts the effective fit too, a rounder lens shape can read slightly larger than a square one at the exact same width measurement.
Signs a frame is the wrong size
- Too wide: the frame extends visibly past the outer edge of your face, or slides down your nose without help.
- Too narrow: you feel pinching at your temples within a few minutes, or the frame looks noticeably smaller than your face.
- Bridge too tight: the frame pinches the top of your nose or leaves marks.
- Bridge too loose: the frame sits low and you find yourself pushing it back up constantly.
- Temple arms too short: the frame doesn't reach comfortably behind your ears without pressure.
Any one of these on its own isn't a dealbreaker, but two or more together usually means the size is off, not just the style.
Common sizing mistakes to avoid
The most common mistake is buying based on how a frame looks on someone else, in a photo or on a model, rather than checking it against your own numbers. The second most common mistake is assuming one brand's "medium" matches another brand's "medium," when the actual millimeter measurements can differ noticeably between brands even at the same label. The third is ignoring bridge width entirely and focusing only on lens width, when a bridge that's too tight or too loose can undo an otherwise well-sized frame.
What if you're between two sizes
If your measurement lands right between two frame widths, lean toward the frame shape rather than the exact number. A slightly narrower frame in a rounder shape can read the same width as a slightly wider frame in a squared shape, so trying on both, or at minimum comparing detailed product photos, matters more than chasing an exact millimeter match. Small differences of a few millimeters rarely make or break a fit on their own.
What to do if there's no size chart
Not every product listing includes exact millimeter measurements. When that happens, look at product photos with a reference object in frame, or check the return policy before buying, since a fair return window covers you if the fit is off. A lifetime warranty on the frame itself, which every Cali Life Co. pair carries, is a separate issue from sizing, but it does mean you're not stuck with a frame that fails structurally even after the fit is dialed in.
FAQ
How do I know what size sunglasses to buy? Measure your face width temple to temple, then compare it to the combined lens width and bridge width stamped inside the sunglasses' temple arm. They should land close to the same number.
What do the numbers stamped inside sunglasses mean? Three numbers, usually in the format 52-18-140, representing lens width, bridge width, and temple arm length, all in millimeters.
What happens if sunglasses are too wide for my face? They tend to slide down your nose and look oversized on your face rather than fitted. That's a sign to size down or try a narrower frame shape.
What happens if sunglasses are too narrow? They pinch at the temples, often within minutes, and look smaller than your face rather than proportional to it.
Do all sunglasses brands use the same sizing system? Most use the same three-number format, lens width, bridge width, and temple length, though exact fit can vary slightly by frame shape even at the same measurements.
Bottom line
Sunglasses sizing isn't a mystery once you know the three numbers to check: lens width, bridge width, and temple length, measured against your own face width. Every pair in the wood sunglasses collection is handcrafted in standard adult sizing from bamboo, walnut, or oak, with TAC polarized UV400 lenses and a lifetime warranty, so getting your numbers right once makes every future pair easier to choose.