If you already own a pair of glasses or sunglasses, you will find the size written on the inside of one of the temples (see label "d." in the below image).

The 3 numbers correspond to the parts of the frame labelled "a.", "b." and "c." and their measurements in mm. These measurements are defined as:

a. Lens width

The width of the lens at its widest point.

b. Bridge width

The minimum width of the nose bridge between the two lenses. This measurement is also known as DBL (distance between lenses).

c. Temple length

The full length of the temple, measured along the curvature of the temple tip. Temples usually come in 3 standard lengths: 135, 140 or 145mm.

If your frames do not have the measurements on them, you can use a ruler or tape measure to measure the above dimensions. 


At Bespectacled, glasses and sunglasses are categorised into S, M and L sizes based on the width of the lens. Please see below table for details: 


Size Width of lens
S less than or equal to 49mm
M 50mm - 54mm
L greater than or equal to 55mm


You can find the measurements of each frame in the product description, under the product details section (highlighted in red below).



As a general rule, the total width of the frame front should be approximately the same width as your face. It is worth noting that differences in design, material and brand mean that frames with the same measurements may not fit in the exact same way. We therefore advise using your existing measurements as a guide but do not be afraid to try styles which deviate slightly from your numbers. With our free 14 day returns policy, if you try on a pair of glasses at home and they do not fit, you can simply return them for a full refund.