How to Choose the Right Glasses Size: Complete Guide
Finding the ideal frame online can seem tricky, but a few simple markers make it easy. On Visionet you can filter by size XS, S, M, L or XL. Step one is to measure your current frame correctly.
1
How to measure your current frame
Measure the overall width at the hinges, from the inside of one temple to the inside of the other, ignoring temple thickness. Size matches:
- XS: 100–122 mm
- S: 123–128 mm
- M: 129–134 mm
- L: 135–140 mm
- XL: 141–155 mm
You don’t need to be exact to the millimetre: if your frame measures 134 mm, choosing a model between 132 and 136 mm is usually perfect. A small tolerance keeps comfort and balance.
Most frames are made in a single size. If multiple sizes exist for a model, the product page will indicate them.
View examples of correct frame measurement
Open the size calculator (enter a width in mm)
2 The key criteria for the right size
Opticians often refer to size by lens width (e.g., 50 or 52). However, the most reliable criterion is the overall frame width. It includes the bridge, temple shape and curve, material thickness—everything that truly affects comfort and aesthetics.
3 Understanding the numbers on the temple
You’ll often see three numbers, for example 50-19-135:
- 50 mm: lens width
- 19 mm: bridge width
- 135 mm: temple length
1 — Temples
Various lengths exist. A difference of about ±5 mm is generally acceptable.
2 — Lenses
The lens width defines the official size. Together with the bridge, it gives an idea of face coverage.
3 — Bridge
This measure isn’t especially critical: it is simply the minimum distance between the two lenses. It’s mainly used to be added to the lens width to provide a general sense of how the frame will sit on your face.
4 Practical tips
If you hesitate between two sizes, choose the one closest to your current pair. Also consider your face shape: certain frames flatter round, square, or oval faces better.
5 Which size for women, men and kids — and how style influences fit
Size choice naturally varies depending on whether the frame is for women, men, or kids. For women, the most common sizes are S and M, delivering a balance of comfort and flattering proportions. That said, bold, larger silhouettes are very popular—especially for sunglasses—bringing a fashion-forward look and broader light coverage.
For men, sizes M, L, and sometimes XL are most common. Jawline and shoulder width often influence the choice: frames that are too narrow can feel tight or look visually unbalanced. Many men prefer more substantial rectangular or square styles for stability and ergonomics—though some intentionally pick slightly narrower frames for a refined or vintage vibe.
For kids, XS and S sizes are recommended, with shorter temples to ensure a secure fit. Oversized frames can slip down the nose or obstruct vision, while well-fitted children’s frames enhance comfort and day-to-day wearability.
Remember that the “ideal” size isn’t just about millimetres. Some frames are designed to be worn larger than the face for a statement look. Oversized acetate styles and certain sun shapes embrace volume and make a strong style point. Conversely, a slightly smaller pair can create a discreet, sophisticated impression.
Lens shape matters too: for example, round frames are often worn a little smaller than square or rectangular models to maintain pleasing proportions. A round frame that’s too wide can overwhelm facial features, while sharper, rectangular silhouettes tolerate more width without visually weighing down the face.
In short, your perfect size blends face morphology, technical measurements, and style intent. Compare your measurements with each product page, use the calculator below, and explore our virtual try-on to validate your choice with confidence.
