Find your fit

Start with a pair you already wear

Look inside the temple arm of your current glasses. Most frames print three numbers there, such as 52-18-140: lens width, bridge width and temple length in millimetres. Write them down along with the total front width, which you measure yourself from hinge to hinge.

Compare those numbers with the measurements on a product page. Within 2 mm of your lens width and total frame width, and within 5 mm of your temple length, a frame will usually feel the same. The bridge is stricter on plastic frames: allow 2 mm where there are adjustable nose pads, but stay within 1 mm on a moulded acetate or TR-90 bridge.

Check a frame against your pair

Enter the three numbers from your current glasses under Will it fit? on any product page, and add the frame width if you know it. You get one short line per measurement: Close match when it is within the tolerance above, Slightly larger or Slightly smaller when it is not, with both numbers in millimetres. Fit my measurements on the frame list uses the same tolerances and shows only close matches.

How a good fit feels

• The bridge rests on your nose without pinching and does not slide when you look down.
• Your eyes sit near the horizontal centre of each lens.
• The temples run straight back and curve gently behind your ears.
• The frame does not lift when you smile or touch your cheeks.
• Your eyelashes do not brush the lenses.

Width matters most

If a frame is too narrow, the temples press on the side of your head and the frame pushes forward. If it is too wide, it slides down and the lenses sit off-centre. The total front width tells you more than the size label alone.

Size labels are a starting point

Our five sizes, from extra narrow to extra wide, help you browse, but they are ranges, not a fit test. Nose shape, the angle of the temples and the curve of the frame also affect comfort. Filtering by size narrows the list; the measurements decide.

When to check with someone

If you have a low nose bridge, very high cheekbones or a strong prescription, a quick check with an optician can save a return. Adjustable nose pads give metal frames more room to fit, and acetate frames can be adjusted at the temples.

The measurements we list

Every product page lists lens width, bridge, temple length, lens height and front width in millimetres. Where a supplier has not given an exact figure, we show an estimate and label it as approximate. The size chart on each product page lets you switch between millimetres and inches.

If you are between sizes

If your face sits between two size labels, start with the bridge. A bridge that fits keeps the frame steady, and a slightly wider front is easier to live with than one that pinches. Metal frames with adjustable nose pads are more forgiving of small differences than acetate frames with a fixed bridge.

Lighter frames are also more forgiving. A thin titanium or TR-90 frame that is a millimetre or two wide will still feel comfortable, while a heavy acetate frame of the same size can slide.

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