Fit
Sunglasses measurements explained: what 60-15-145 means and which number decides fit
The three numbers printed on the inside of a sunglasses arm are lens width, bridge width and temple length, in millimetres, always in that order. A frame marked 60-15-145 has 60mm lenses, a 15mm bridge and 145mm arms. The number that actually decides whether a frame fits your face, the total frame width from hinge to hinge, is usually not printed at all. Here is what each number means, why the printed three can mislead, and how to measure your own face in thirty seconds.
The three printed numbers
Look on the inside of either temple arm. You will find three numbers, often separated by a small square or a dash.
| Number | What it is | Typical range |
|---|---|---|
| First (e.g. 60) | Lens width: the horizontal width of one lens at its widest | 40 to 62mm |
| Second (e.g. 15) | Bridge width: the gap between the two lenses at their closest | 14 to 24mm |
| Third (e.g. 145) | Temple length: the arm, from hinge to tip | 120 to 150mm |
Lens width is measured by the boxing system: the width of the smallest rectangle that encloses the lens. It is a width, not a diameter, so a rectangular lens and a round lens with the same number look very different.
Bridge width is the gap between the lenses, not the width of the nose piece. A wider bridge suits a wider nose and sets the lenses further apart.
Temple length is the arm. Almost all adult frames fall between 135 and 150mm, and the difference between them rarely decides comfort; the bend behind the ear does more.
The fourth number, and why it matters most
Frame width is the whole front, hinge to hinge. It is roughly two lens widths plus the bridge plus the rims, and it is the number that decides whether a frame sits on your face or hangs off it.
Most makers do not print it. Ours is stated on every product page: 140mm, from the frame maker's published diagram. That is a medium-wide frame.
The rule of thumb is simple. Measure the width of your face across the cheekbones at the widest point, temple to temple. A frame within about 10mm of that number will fit. A 140mm frame suits a face of roughly 130 to 150mm. Below about 125mm it will look oversized.
Why lens width alone misleads
Two frames with identical lens widths can fit completely differently, because the bridge sets how far apart the lenses sit. A 55mm lens on a 22mm bridge makes a wider front than a 55mm lens on a 14mm bridge. This is why comparing lens widths between brands is unreliable, and why frame width is the number to trust.
How to measure your face
- Stand in front of a mirror with a ruler that shows millimetres.
- Hold it horizontally across your face at the level of your eyes.
- Read the distance from the outer edge of one temple to the outer edge of the other, at the widest point of the cheekbones.
That number is your frame width. Most adult faces fall between 125 and 150mm.
If you have a pair that fits well, you can skip the mirror: measure that frame across the front, hinge to hinge, and use that.
Reading our numbers
Every T01 on this site is 60-15-145 with a 140mm front and a 50mm lens height. Those are the frame maker's published figures, taken from their size diagram, and the fit guide draws the diagram to those numbers. The maker's own listing gives two lens widths, 60mm on the diagram and 5.2cm in a table, which most likely describe the lens opening with and without its rim. We publish 60 because that is what a lens width normally means.
What the numbers do not tell you
- Lens height is rarely printed and matters for coverage: a shallow lens lets light in from below.
- Wrap or base curve is how much the front curves around your head. Not printed on the arm.
- Weight is never on the arm.
- Face shape is not a measurement at all. Our face shape post covers what shape does, but width decides fit and shape decides what flatters, and width matters more.
Frequently asked questions
What do the numbers on sunglasses mean?
Lens width, bridge width and temple length, in millimetres, in that order. 60-15-145 is a 60mm lens, 15mm bridge and 145mm arms. They describe the parts, not the whole front.
How do I know what size sunglasses to buy?
Measure across your face at the cheekbones and look for a frame width within about 10mm of that. If the maker does not print frame width, add two lens widths, the bridge and about 6mm for rims to estimate it.
Is 60mm lens width big?
It is at the wide end for a rectangular frame. On a 15mm bridge it makes a front around 140mm, which suits a medium to wide face. On a narrow face it will look large.
What size sunglasses for a small face?
Look for a frame width under about 130mm, which usually means lens widths in the low 50s or below on a narrow bridge. Our T01 at 140mm is a medium-wide frame and is not the right choice for a small face.
Does temple length matter?
Less than the other numbers. Most adult arms are 135 to 150mm and the bend behind the ear absorbs the difference. Very long arms can slide; very short ones pinch.
Sources
- American Academy of Ophthalmology. How to read your eyeglass prescription and frame measurements. www.aao.org
- ANSI Z80.5-2020, American National Standard for Ophthalmics: Requirements for Ophthalmic Frames. Defines the boxing system for lens and bridge measurement. webstore.ansi.org
Measurements on this site are the frame maker's published figures, attributed on every page that prints one. This is general information about sunglasses, not medical advice.
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