How are sunglasses measured?

Sunglasses are measured by three aspects; lens width, bridge width and temple length. Usually labelled on the inner temples (arms) of your frame, these measurements are in millimetres and may be separated by a small square, dash or space. Eg: 63 [] 18 145.


If you have well-fitting spectacles or sunglasses, it can be really helpful to take a note of these measurements and use them as a guide for your next new pair. As your facial dimensions won't change, you can even memorise these like your shoe size.

But what if you struggle to find sunglasses that fit?

Scroll below for a helpful guide on how to measure sunglasses for your head size.


Man with ruler across his face measuring the distance between his temples

How do I know my sunglasses size?

To know your sunglasses size, hold a ruler horizontally across your face to measure the distance between your temples in either cm or inches. You can check your ideal sunglasses size via the table below.

Your temples are the soft skin located just outside your eyes towards your ears (above your cheekbones).

It’s best to use a ruler for this measurement because it stays straight like a sunglasses frames; unlike a tape measure which can bend and needs two hands to use.

Face size (cm)

Face size (inches)

Sunglasses size

11.5cm – 13cm

4.5” – 5.1”


13.5cm – 14cm

5.25” – 5.5”


14.5 – 16cm

5.75” – 6.25”






What do the 3 numbers on sunglasses mean?

The 3 numbers on sunglasses denote the key measurements of the frame which include the lens width, bridge width and temple length. In this particular order, these 3 sets of digits are usually labelled on the interior surface of the frame, most commonly on the temple arms. For example 55 [] 22 145

55 = lens width (in mm)

22 = bridge width (in mm)

145 = temple length (in mm)

For a more detailed explanation about how to measure these aspects of a sunglasses frame, scroll below.


Man wearing Aviator sunglasses with white arrow diagram across one lens

How do I know my lens width?

To know your lens width, use a plastic ruler (to prevent scratches) to measure one of your sunglasses lenses from their widest outer-edges. This measurement is always taken in millimetres and is the first set of digits labelled on your frame. Eg: 55 [] 22 145.

Adult sunglasses lens widths typically range between 49mm and 63mm.

Lens width

Sunglasses size

49 - 54mm


55 - 57mm


58 - 63mm




Man wearing Aviator sunglasses with white arrow diagram across the nose bridge

How do I know my bridge width?

To know your bridge width, measure the inner-most distance between your lenses in millimetres. Then minus this number by 3. Your bridge width is the second set of digits labelled on your frame. Eg: 55 [] 22 145.

For example, if the distance between your lenses (DBL) is 23mm, your frame has a 20 mm bridge width.

Adult sunglasses bridge widths typically range between 14mm and 25mm.

Bridge width

Sunglasses size

14mm - 17mm


18mm - 21mm


22mm - 25mm




Side view of man wearing Aviator sunglasses with white arrow drawn across the temple length

How do I know my temple length?

To know your temple length, measure (in mm) from the hinge to the bend and then from the bend to the temple tip. Combined, these measurements are your temple length which are the last set of digits labelled on your frame. Eg: 55 [] 22 145.

Adult sunglasses temple length typically range between 120mm and 150mm. However, it is common that temple lengths aren’t always stated by certain brands and manufacturers.

Temple length

Sunglasses size

120mm - 130mm


130mm - 140mm


140mm - 150mm



Extra Large



UV400 printed on the inside of a black sunglasses arm

What is UV400?

UV400 means sunglasses lenses can protect your eyes up to the 400-nanometre wavelength of ultraviolet (UV) light. With regards to skin and eyecare, UV400 sunglasses protect you from the most dangerous range of electromagnetic exposure. UV400 and UV40 mean the same thing.

UV light sub-type

Frequency (nm)

Danger to eyes & skin


315 - 400



280 - 315



100 - 280



Are darker sunglasses better?

No, the darkness of your sunglasses is purely for visual comfort and has no relevance to UV protection. Darker sun lenses simply absorb more visible light which can reduce strain on your eyes. UV protection (UV400) is a mandatory requirement of any sunglasses frame which blocks UVA and UVB light from damaging your eyes.

So you know, the darkness of sunglasses is classified by their level of absorption. Darker lenses absorb more visible light, whilst lighter lenses absorb less. This is what denotes the 5 sunglasses categories.


What does CE mean on sunglasses?

CE stands for Conformité  Européenne. (French for "European Conformity.) Spectacles and sunglasses which are compliant with EU health, environment and safety regulations must bear the CE mark. This emblem is usually labelled on the inner surface of the temple or frame, marked via pad printing or laser etching.



White measurement numbers printed on a tortoiseshell sunglasses arm

What measurements do I need to order glasses online?

To order glasses or sunglasses online, it’s good to know your ideal lens width, bridge width and temple length. These measurements help you select the correct size of frame for a proper fit. For ordering prescription lenses, you’ll need an up to date prescription and your pupillary distance (the distance between your pupils in mm.)

Hopefully you found this article helpful. Please check out our other sunglasses blogs for more useful advice. Thanks for stopping by.


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