Guides
A guide to frame measurements
Five numbers describe any pair of glasses. Here is what each one means, where to find it, and which ones actually matter when you buy.
Step by step
Reading the numbers on your frame
Look inside the temple arm
Fold the glasses and look at the inner face of either arm. Most frames carry a marking such as 51□21-145 near the hinge.
Read lens, bridge, temple
The first number is the lens width, the second is the bridge, and the long number is the temple length. The little square is just a separator.
Compare like with like
Fit is driven by lens plus bridge. Two frames within 2 mm of yours on both will feel the same on your face.
Typical adult ranges
| Measurement | Typical range | How much it matters |
|---|---|---|
| Lens width | 44 to 58 mm | Most important |
| Bridge | 14 to 24 mm | Important |
| Temple length | 135 to 150 mm | Flexible, least important |
| Lens height | 28 to 45 mm | Matters for varifocals |
| Frame width | 125 to 150 mm | Overall face fit |
Know your numbers?
See every frame we stock in your size.
