Size and fit:what the millimetres mean

Every Helio® frame lists three numbers, in millimetres, always in the same order: lens, bridge, temple. Written out, it looks like 52 · 20 · 145. They are printed inside the arm of almost every pair of glasses ever made, including the ones you are probably wearing.

What each number does

 
• Lens width. How wide each lens is, and the biggest driver of how large the frame looks. Larger suits wider faces and bolder looks.
 
• Bridge. The gap between the lenses, where the frame rests on your nose. A smaller bridge suits a lower or narrower nose.
 
• Temple. The length of the arms to your ears. On kids' frames these adjust, so one pair grows with them.

Of the three, lens width does most of the work. If you only compare one number against a pair you already own, compare that one.

The three sizes

Most of our frames come in one of three overall sizes. Faces don't sort neatly into three, so treat these as starting points rather than rules. Every pair adjusts at the nose and the arms, and if the first one isn't right, swap it free inside 30 days.

Small

Best for smaller or more delicate faces. A lighter look that doesn't overwhelm.

Medium

Our most popular fit, comfortable across a wide range of faces.

Large

For broader faces, or anyone who likes a bolder, larger frame.

The quickest route to your size is a pair of glasses that already fits you well.

The easy way: measure a pair you already own

 
• Find the numbers. Look on the inside of one arm. Most glasses print the three measurements there, in millimetres.
 
• No numbers? Measure the lens. With a ruler, measure the width of one lens at its widest point. That is your lens width, the most important of the three.
 
• Match it to ours. Pick a Helio® frame within two or three millimetres and you will be close enough.

Kids: one pair that grows with them

On kids' frames the temple arm adjusts longer or shorter, so a single pair fits from about six to twelve. You don't need to measure to the millimetre. There is room to grow, and the same real lenses as the grown-up frames, built to be knocked about.

Two quick ones

What if I'm between sizes? Go by the lens width first. If you like a snugger, more discreet look, size down. For more coverage or a bolder frame, size up.

Do the arms adjust on adult frames? Adult arms are a fixed length. Only the kids' frames adjust. If an adult pair needs a small tweak to sit right, most opticians can adjust the fit for you.

Still deciding what suits you rather than what fits you? The face-shape guide is the other half of this.