Eyeglasses size

Knowing how to read your eyeglasses size will help you find the best fit, especially when shopping for glasses online. Your glasses size is made up of 3 numbers that indicate measurements in millimeters, such as “45 20-135.” The first number will be the eye size, which measures the width of 1 lens. The second number indicates the bridge width, or the distance between the lenses. The third number, or the temple length, tells you how long the arms of the glasses are. To find the perfect fit, you can take your own measurements or have them taken by an optician. Use your measurements to find a comfortable and flattering pair of eyeglasses with the perfect fit!

Look for a series of numbers on the inside of your glasses. The measurements should be printed in a small font on the inside of the temple, the bridge, or the earpiece. Your glasses’ manufacturer may also group in extra information with the measurements, such as words and or symbols, but you only need the 3 main numbers to determine your size.
  • Different manufacturers write out measurements slightly differently, which can make reading the measurements seem daunting, but just remember to look for the series of 3 numbers. For example, the same measurement could be written "Brand Model 45/20 135," "45-20-135," or "45 20-135."
  • Any words or numbers grouped together with capital letters, such as "ESJ-213" or "O17," represent the frame style or color. Don’t worry about these, since they aren’t relevant to the size measurements.
Find the first 2-digit number to read your eye size. This number measures the width of 1 lens, spanning the distance at its widest point. Your eyes size is the only measurement that falls between 40 to 60 millimetres (1.6 to 2.4 in), so you can use this range to ensure that you’re reading the correct number.
  • For example, if your measurements are "45 20-135," your eye size would be 45 millimetres (1.8 in).
  • For bifocals and progressive lenses, manufacturers will often break down the lens width and height into separate measurements.

Locate the second 2-digit number, or the bridge size. Your bridge size measures the part of your glasses that goes across your nose and connects the two lenses. In the series of 3 numbers, your bridge size will be the only number that falls between 14 to 24 millimetres (0.55 to 0.94 in). It may be printed directly after the eye size, or it might be separated by a small box symbol or a slash.

  • For example, if your measurements read "45 20-135," your bridge size would be 20 millimetres (0.79 in).

Find the third number, which measures your glasses’ arm length. The arm length measures the pieces that extend back to rest over the ears. This measurement will be the only 3-digit number falling somewhere between 120 to 150 millimetres (4.7 to 5.9 in), and sometimes it may be separated from the other two measurements by a dash, extra space, model number, or color number.

  • For example, if your measurements are "45 20-135," your temple length would be 135 millimetres (5.3 in).
  • Some of the most common arm measurements include 135 millimetres (5.3 in), 140 millimetres (5.5 in), 145 millimetres (5.7 in), and 150 millimetres (5.9 in).