Look inside the left temple of any pair of sunglasses and you will find something like 54 □ 18 145. Those three numbers are the size of the frame, and they are the difference between a pair that sits perfectly and one that slides down your nose or pinches your temples. Here is how to read them.
The three numbers
- 54 = lens width, in millimetres, measured horizontally across one lens. This is the number that decides whether a frame looks small, medium or large on you. Most adult frames go from 48 to 60.
- 18 = bridge width, the distance between the two lenses, where the frame sits on your nose. Usually 14 to 24. A narrow bridge (14–17) suits a thin or low nose; a wide one (20–24) suits a wider or higher nose.
- 145 = temple length, the length of the arm from the hinge to the tip, in millimetres. Usually 135 to 150. It matters less than the first two: temples bend behind the ear, so a few millimetres either way are fine.
Some brands also print a fourth number, the lens height (for example 42). The taller the lens, the more of your face the frame covers.
Find your size in 30 seconds
You do not need to measure your face. Take a pair of sunglasses or glasses that already fits you well and read the numbers inside the temple. That is your reference size. When you shop, look for a lens width within 2 mm of your reference and a bridge within 2 mm: the frame will fit the same way.
No pair at hand? Measure the width of your face from temple to temple with a ruler, in millimetres, and use this rule of thumb:
| Face width | Size | Lens width to look for |
|---|---|---|
| under 129 mm | Small | 48–52 mm |
| 130–139 mm | Medium | 53–56 mm |
| 140 mm and over | Large | 57 mm and over |
Another quick check: the total width of the frame (lens + bridge + lens, plus a few millimetres of rim) should be roughly equal to the width of your face. If the frame is clearly wider than your temples, it will slide; if it is narrower, your eyes will look too close together.
Where to find the size on our site
Every product page shows the brand's model reference (for example PR 17WS or BB0095S). The size is printed on the frame itself and usually appears in the product description; when a model exists in several sizes, the size is part of the reference (the 53-19 in FN000796 1100B1 53-19). If you cannot find it, email us the model name and we will send you the exact measurements.
Small, medium or large: a few examples
Small and delicate (lens around 50–53 mm):
Slim oval metal frame. Light on the face, ideal for narrow faces.
Women's Oval Gold/Green Sunglasses - Gentle Monster Musubi 031
A compact oval, one of the most delicate shapes in the catalogue.
Medium, the safe choice (54–56 mm):
Prada Symbole PR 17WS Sunglasses
Rectangular acetate, standard proportions that fit most faces.
Céline Triomphe CL40308U Sunglasses
Rounded acetate with a little height: medium size, strong presence.
Large and oversized (57 mm and over, or a single shield lens):
Balenciaga Dynasty D Frame BB0095S Sunglasses
A wide D-frame that covers a lot of the face. Made for medium to large faces.
Alexander McQueen AM0313S Sunglasses
One continuous lens: the width of a large frame with the look of a visor.
Fit problems and how to read them
- The frame slides down your nose: the bridge is too wide, or the frame is too heavy for the bridge. Look for a narrower bridge (2 mm less) or a frame with adjustable nose pads.
- The frame pinches at the temples: the frame is too narrow. Go up 2 mm in lens width or pick a model with a wider bridge.
- Your eyelashes touch the lenses: the frame sits too close. A frame with nose pads, or a slightly wider bridge, moves the lenses forward.
- The frame sits crooked: usually one temple is bent, not a size problem. Any optician will adjust it in two minutes, often for free.
Not sure? Ask us
Send the size of a pair that fits you and the model you like to contact@skyeshades.com: we will confirm whether it will sit the same way. Shipping is free and tracked worldwide, and you have 14 days to return a pair that does not fit. Start with our best deals.