Finding the Right Size Sunglasses

A Simple Fit Guide

Credit Card Measurement Method

Sunglasses should fit as well as they function. With the perfect fit, your shades will remain comfortably on your face, protecting your eyes without pinching your nose or ears, sliding down, or causing headaches. Our unique fit guide leverages a common item: a credit card. With its standard width of 54mm, credit cards are useful tools to measure your face, providing a reliable indicator of your head size and, by extension, the size of the sunglasses you need.

1. Position the Card

Place the credit card flat against your face, aligning the edge of the lengthier side with the middle of your nose.

2. Determine Your Size

Note where the card extends in relation to your eyes to identify your optimal size: small, medium, or large-XL.

3. Choose Your Shades

Every style of Melonz sunglasses comes in all three sizes, so once you know your size, you're good to go!


For head circumferences of 21-22 inches, with frame widths of 115-130mm. The credit card extends beyond the outer corner of the eye, suggesting a smaller frame for narrower faces.


Suited for head circumferences of 23-inches, with frame widths between 131-139mm. If the card roughly aligns with the outer corner of the eye, a medium frame will provide the optimal fit.


Designed for head circumferences of 24-25 inches, requiring frame widths of 140mm or greater. When the credit card does not reach the outer corner of the eye, a large-XL frame is recommended.

By measuring frames from hinge to hinge, we directly address the distance between a person’s ears, considering that the distance from eye to ear slightly increases with wider head widths. This method ensures that our frames not only fit the width of the face comfortably but also rest snugly over the ears, avoiding any discomfort or need for constant readjustment.

It’s not just the width that matters; the distance from the frame to the ears plays a crucial role in ensuring comfort. That’s why each of our frames is designed with custom temple lengths suited to the frame size, providing a seamless fit from the nose bridge to the ears.

The measurement of the bridge—the section of the glasses that rests on your nose—is equally crucial. A well-fitting bridge ensures that your sunglasses sit securely and comfortably, without slipping or pinching. Whether you have a narrow, medium, or wide bridge, our detailed sizing guide helps find the optimal fit, promising comfort and stability in every wear.