Ask an Optician: Which Frame Size Will Fit Me?
Overview
The right frame size depends on your face shape, pupillary distance and how the glasses sit on your nose and ears. The easiest way to find your perfect fit is to check the measurements printed inside your current frames, or use your face width as a guide.
Measurements to know
Before choosing your next pair of glasses, it’s helpful to understand the three key measurements of parts of glasses that influence both fit and comfort:
- Lens width: The horizontal width of each lens, which affects how the frame suits your face.
- Bridge width: The distance between the two lenses, determining how the glasses rest on your nose.
- Temple length: The length of the frame arms, which affects how securely the glasses sit behind your ears.
Option #1: Check the measurements engraved on your glasses
Most glasses have measurements printed inside the frame arm. These numbers describe how wide the lenses are, how far apart they sit and how long the arms are. Together, they determine how your glasses fit your face.
If you already own a pair that fits comfortably, start by matching those numbers when shopping for new frames online.
A small difference of 1–2 mm in either direction usually won’t affect comfort, but bigger changes can alter how securely your glasses sit.
Option #2: Measure your glasses
If the measurements inside your frame are faded or hard to read, you can measure them yourself using a ruler or millimetre tape.
- Lens width: Measure the widest part of one lens horizontally.
- Bridge width: Measure the distance between the lenses acros the nose area.
- Temple length: Measure the full length of one arm from the hinge to the tip that rests behind your ear.
Write these three measurements down, for example: 52-18-140, and use them as a reference when browsing frames online. This method gives you a reliable estimate of your current fit without needing to visit an optician.
Option #3: Measure your face
If you don’t have an old pair of glasses to reference, you can measure your face directly to find the right frame size.
Use a ruler or measuring tape and measure across your temples, from one side of your face to the other.
Compare that number with the approximate frame width:
- 115–129 mm: Small frame size
- 130–139 mm: Medium frame size
- 140–150 mm: Large frame size
The frame should sit comfortably on your nose, without sliding down, and should align with your temples without pressing against them.
Buying the right size frames on SmartBuyGlasses
Once you know your measurements, shopping for the right frame size on SmartBuyGlasses is simple.
When you click on any product, you’ll see a “Fit & Size Guide” pop-up (as shown below) that helps you match your measurements to the correct frame category.
This guide breaks down the key dimensions: lens width, bridge width and temple length, and groups them into size ranges from extra-small to extra-large.
To dive deeper, check out our related guides:
EXPERT'S TIP!
“If you’re between sizes, always choose the slightly smaller frame. Glasses that are too large are harder to adjust and may slip more easily, especially with heavier lenses.”
Maria Horan, Dispensing Optician
With the SmartBuyGlasses Fit & Size Guide, you can shop confidently knowing your new frames will match your style and fit comfortably from day one.
Your comfort matters
The right frame size ensures your glasses look good, feel comfortable and provide clear vision all day. If they’re too tight, loose, or wide, you’ll notice it quickly.
And if you’re not completely satisfied, you can shop confidently knowing SmartBuyGlasses offers a 100-day return policy on all eyeglasses and sunglasses.
Still unsure about your perfect fit? Speak to one of our certified optical experts for personalised advice.
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