How to Read Eyeglasses and Sunglasses Frame Measurements

What the three numbers mean

A code such as 52–18–140 usually gives lens width, bridge width and temple length, in millimetres and in that order. Lens width measures one lens, bridge width measures the space between lenses, and temple length describes each arm from hinge to tip. Check the seller’s key for the model because formats and the fields supplied can vary.

Warby Parker’s measurement guide illustrates where these numbers appear and what they represent.

Use a frame that already fits as a reference

Read the numbers inside a pair you find comfortable, then compare each measurement with the candidate frame. A close match is a starting point, not a promise: total frame width, bridge shape, nose pads, lens height and the curve of the temples also affect how a frame sits. Two frames with the same lens and bridge numbers can still feel different.

If the listing omits total width or bridge details, record that as unknown. Do not infer those measurements from a product photograph or convert a lens width into a face-width guarantee.

When fit needs a professional check

For prescription eyewear, stronger prescriptions, unusual bridge fit or discomfort, ask an optician to check the frame and lens requirements. A retailer’s “standard fit” label is not an individual fitting. PowderedPurple product profiles show the fields that were published for a listing and identify missing measurements where possible.

You can also browse listings with all three measurements recorded. This directory reflects only the current catalogue coverage.

Browse eyeglasses or see the eyewear hub.