If you're unsure what size you are and want to be 100% sure your nails will fit, you can order a sizing kit from my shop. It's important you use the sizing kit from my shop as some other sellers might be using other different brands of nails with completely different sizing. Make sure you order the sizing kit on the shape you will order in the future as some shapes vary sizes slightly. Or, you can purchase a full set of 20 or 24 nails.