How To Measure Your Frame Size

In this guide

How to Measure Frame Size

Most glasses have size numbers printed inside one of the temple arms (side arms). These numbers are usually written like this:

Example: 52 – 18 – 140

These numbers mean:

  • 52 = Lens width
  • 18 = Bridge width
  • 140 = Temple length

If your current glasses fit well, you can use these numbers when ordering a new frame.

Diagram showing lens width, bridge width, and temple length on a frame
Diagram showing lens width, bridge width, and temple length on a frame

Frame measurements help you find glasses that fit comfortably and look great.
You’ll usually find three numbers printed inside the temple arm (e.g., 56 □ 18 – 140).

Lens Width
Lens Width

Lens Width

The width of one lens, measured horizontally at its widest point. This is the most important measurement for overall fit.

Typical range: 40 mm – 60 mm

Bridge Width
Bridge Width

Bridge Width

The distance between the two lenses that sits on your nose. A proper bridge fit ensures comfort and prevents slipping.

Typical range: 14 mm – 24 mm

Temple (Arm) Length
Temple (Arm) Length

Temple (Arm) Length

The length of the arm that goes over your ears. It affects how securely the glasses stay in place.

Typical range: 120 mm – 150 mm

Lens Height
Lens Height

Lens Height

The vertical height of the lens from top to bottom. Important for style and especially for progressive lenses.

Typical range: 25 mm – 50 mm