1. Measure your natural nails
Use a flexible measuring tape or a piece of paper and a ruler to measure the widest part of your natural nail bed (usually near the cuticle) in millimeters. Do this for all ten fingers, as sizes can vary.

2. Match the width to the nail sizes
Compare your measurements to the sizing chart provided below. Match the closest size to your nail width.

3. When in doubt, size down
If you’re between two sizes, choose the smaller size. It’s better for the press-on nail to be slightly smaller and sit securely on the nail bed than to overlap your skin or cuticle, which can lift or cause discomfort.

4. Customize if needed
You can gently file the sides or base of the press-on nail to better fit your nail shape. Use a fine-grit file and take your time to avoid damaging the nail.