Sunglasses Size Calculator
Understand sunglasses measurements.
Sunglasses are labeled e.g. 52□18 140.
How the Math Works
Sunglasses sizing follows a standardized three-number system where the first number represents lens width, the second the bridge width, and the third the temple length. These measurements work together to determine overall fit: total frame width equals lens width plus bridge width plus approximately 10-15mm per temple. The mathematical relationship ensures proportional balance - if your face width is 140mm, a frame with 52mm lenses, 18mm bridge, and 140mm temples will wrap correctly without pressure points.
Practical Applications
To apply these measurements, first measure your face width at the widest point just above your ears, then measure your bridge width across the nose. Compare these to frame specifications: if your face is 145mm wide, choose frames where lens width plus bridge width totals approximately 70-75mm. Test fit by ensuring temples extend comfortably past your ears without pressure, and that the frame sits level across your nose without sliding down.
Day-to-Day Use
Understanding these measurements prevents common eyewear issues like frames that slip, pinch, or leave red marks. When shopping online, you can confidently select frames that match your facial dimensions, reducing returns and exchanges. This knowledge also helps you communicate effectively with opticians, request specific adjustments, and determine when frames need replacement due to wear that affects their original sizing proportions.
FAQ
What fits?
Match lens width to a pair that fits well.