It's important to measure your nails accurately and with patience using a ruler or measuring tape marked in millimeters (mm).

Please follow these steps:

1. Measure Each Nail: Place the ruler or measuring tape across the widest part of each nail. Record the measurement in millimeters (mm) for each finger.
2. Write Down Your Sizes: Keep a record of these measurements for your order and for future reference for each style.
3. Different Styles: Since nail sizes can vary between different styles, always refer to your recorded measurements when selecting new press-on nails.
4. Sizing Kit: an easier way to get your measurements which you can find in the press on nails section. Pick the nails that fit each nail and write down your measurements for your order and future reference.

Taking the time to measure your nails will help you achieve the best look and comfort with your press-on nails.