The Kids Twirly Dress has a fitted top portion with a twirly bottom. Choose sleeveless, short, half, or 3/4 sleeved banded. The length is measured from the childs nap of neck to the hem. For reference, the 2/3yo tunic is about 5" shorter than the dress length and sizes smaller will have less difference and sizes larger will increase in difference.
For our lightweight merino-tencel fabric consider sizing down one size to take into account their amazing stretch.