Finding the right sized Glasses & Sunglasses

A guide to understanding the frame measurements on your eyeglasses.

If you’re buying a new pair of glasses or sunglasses online you need to know the correct frame size for you in order to ensure the perfect fit. Fortunately, if you’re an existing glasses wearer it’s easy to find this information on your current frames. In this handy guide we’ll give you all the information you need to know to ensure your buying experience is hassle free.

Method 1: Measure Your Frame Size Using Your Current Frame Measurement

Look Into Your Frame's Temple and follow the given steps below


The Numbers on your Glasses

If you’re a glasses wearer you may notice some numbers on the arms or the bridge. These numbers usually include the frame model, colour code and measurements, as illustrated.


The numbers, 55 [] 18 – 145 (in millimetres) displayed in this image indicate the following:-


  • 55 (mm) will represent the width of the lens. Usually a 2 digit number in the 40-62mm range.
  • 18 (mm) will represent the width of the bridge. Usually a 2 digit number in the 14-24mm range.
  • 145 (mm) will represent the overall length of the arm. Usually a 3 digit number in the 110-150mm range.

Our video guide below will help you find these numbers.

Understanding the Frame Measurements

The diagram below illustrates the fundamental elements and component parts which make up the spectacle frame. In terms of the fitting of the spectacle frame, the bridge is perhaps the most important part to consider when choosing your frames, because it is here that the major bearing surface and area of contact between the front and the face is situated. The bridge design should facilitate a comfortable and supportive fit which will maintain the position of the lenses over your eyes with a natural gaze.

The Bridge Width

The bridge width is the minimum horizontal distance between the nasal surfaces of the rims on a plastic or metal frame, or the minimum horizontal distance between the nasal surfaces of the lenses in rimless frames.

If a frame has adjustable nose pads on metal arms various modifications can be made in order to achieve a satisfactory fit

The Lens Width

The lens width is the distance between the vertical sides of a rectangle containing the lens shape. The sizes for the lens width and bridge width can usually be found on your current glasses by looking on the inside of the frame

The Arm Width

The arm length is measured from the dowel point to the extreme end of the side, this is made up of the length to the bend and the length of the drop to give the overall length of side.

Overall Frame Width

Another measurement to consider would be the overall width of the frames. Aside from 2x the lens width + the bridge width, the overall width is also dictated by factors such as the thickness of the rim of the frame and how swept out the lugs are.

Method 2: Measure Your Frame Size Using Credit Card

First Look Into The MIRROR And Follow the Given Steps Below

  • Take any credit or debit card.
  • Stand in front of a mirror or place your smartphone somewhere steady and use your selfie camera. Place the credit card on the bridge of your nose and under your eyebrow.
  • If the edge of the card extends further than the edge of your eye, you are a small size (size: S)
  • If the edge of the card ends at the outer edge of your eye, you are a medium size (size: M)
  • If the edge of the card ends before the outer edge of your eye, you are a large size (size: L)

Frame Size Categories:

Frame Size Spectacles(Lens Width)
Small Size 40-48 mm
Medium Size 49-54 mm
Large Size 55 above