Glasses Frame Size Guide: What 52-18-140 Means
The easiest way to find your size is to look at your current glasses. Most frames have three numbers printed on the inside of the temple.
Lens width (first number)
The width of each lens in millimeters, for example 52.
Bridge (second number)
The distance between the lenses, over your nose, for example 18. A narrow nose bridge needs a smaller number.
Temple length (third number)
The length of the arm, for example 140. Most adults fit 135 to 150.
Total width
Roughly 2 × lens width + bridge + about 10 mm. Under 130 mm is small, 130–139 medium, 140–145 large and 146+ extra large.
Tip
Choose frames within 2–3 mm of your current measurements for a similar fit.
Frequently asked questions
My glasses have no numbers. What now?
Measure the width of your current frame across the front with a ruler and compare total width.
What size fits most people?
Medium (about 130–139 mm total width) fits most adult faces.
Related guides
This guide is for information only and does not replace an eye exam. If you have eye pain, sudden vision loss or flashes of light, see a doctor right away.