Measurement around waist to determine band size. Hold measuring tape snug against the skin just below the bust underneath your breasts and breathe regularly.
BOTTOM CUP DEPTH
Measurement from the middle of the breast to the bottom lengthwise. Start with bringing the end of the measuring tape against the center of your nipple. Keep measuring tape in place with one hand and lift breast up with same hand. Use other hand to bring the tape straight down until you hit the point where your breast ends, commonly known as your wireline where your wires would normally sit at the breast root.
Measurement from one end of the breast to the other widthwise. Start in the middle of your chest where your breast tissue begins. Use one hand to keep the tape in place, and use the other hand to cross tape over your breast, crossing over your nipple or your apex (pointiest part). Come over and around to your underarm area and stop where your breast tissue ends. If you're not wearing a bra, slightly bend over to make this measurement easier.
Start measuring tape on top of your shoulder bone and bring it down to where your bra strap would attach to the cup. Common range is between 5-8 inches. Ideal if wearing a bra but not necessary.