Glasses Size Guidance
Find your perfect fit: learn what the numbers mean (e.g., 54–17–140), how to measure, and which size suits you.
The Three Key Numbers
Lens Width
Measured horizontally at the widest point of one lens (e.g., 54 mm). Affects how the glasses look on your face and your field of view.
Bridge Width
The distance between the lenses (e.g., 17 mm). Impacts how the frame sits on your nose.
Temple Length
The length of the arms (e.g., 140 mm). Impacts ear comfort and stability.
You’ll often see sizes printed inside the left temple like: 54–17–140 (Lens–Bridge–Temple).
What Size Should I Choose?
As a quick rule: match your current frame’s numbers, or stay within ±2 mm for lens width and ±1 mm for bridge width.
| Face Width (approx.) | Suggested Lens Width | Typical Bridge | Temple |
|---|---|---|---|
| Narrow | 48–51 mm | 16–18 mm | 135–140 mm |
| Medium | 52–55 mm | 17–19 mm | 140–145 mm |
| Wide | 56–59 mm | 18–21 mm | 145–150 mm |
Check Your Fit
PD (Pupillary Distance)
PD is the distance between the centres of your pupils (in millimetres). It helps position your lenses correctly.
- Stand in front of a mirror with a ruler held flat against your brow.
- Close your right eye and align the “0” with the centre of your left pupil.
- Open your right eye, close your left, and read the millimetre mark at the centre of your right pupil — that’s your PD.
Typical adult PD: 58–72 mm. If you have a recent prescription, it may already list your PD.
Size & Fit FAQ
What if my exact numbers aren’t available?
Stay close: lens width within ±2 mm, bridge within ±1 mm, temple within ±5 mm usually feels familiar.
Do lens thickness or prescription affect fit?
Yes. Higher prescriptions may benefit from smaller lens widths and higher-index materials to reduce edge thickness.
Can you adjust temples and nose pads?
Most metal frames and acetate temples can be micro-adjusted. If unsure, ask an optician to fit them to you.