Frame Size & Fit Guide

Every pair of glasses has its size printed inside a temple arm: three numbers like 49-20-145. Decode those and you can size any frame on the internet, ours included.

The three numbers

• Lens width (49): the horizontal width of one lens in millimeters. Most adult frames run 44–58 mm.
• Bridge (20): the gap between the lenses, over your nose. Narrow bridges (16–18) suit low nose bridges; wider (20–24) suit prominent ones.
• Temple length (145): the arm, from hinge to tip. 135–150 mm covers nearly everyone.

If you own a comfortable pair already, its numbers are your baseline — match within 2 mm on lens and bridge and you'll be close.

No current pair? Measure once

With a mirror and a millimeter ruler, measure the distance between your temples across your face. That's your target total frame width. Each Meridian product page lists total width alongside the three standard numbers.

How a good fit behaves

• The frame ends at your temples — no digging, no overhang.
• Nothing touches your cheeks when you smile.
• Glasses stay put when you look down and shake your head.
• Weight rests on the nose bridge and behind the ears equally, and eyelashes clear the lens.

Small problems are adjustment problems

Sliding, tilting, or one-side-high sit are ten-minute fixes, not reasons to return a frame you love. Any optical shop will adjust a frame (usually free, always cheap), and our Warranty & Adjustments page explains what we cover. Kids' fit has its own rules — see our blog guide to kids' frames.