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
This is the vertical measurement of the breast from the middle of the nipple to the bottom of the breast. If you're wearing a good non-padded bra, you can do this while keeping the bra on. If not, measure without a bra on.
Start with bringing the the top of the measuring tape (at the zero mark) against the center of your nipple. Keep measuring tape in place with one hand and cup your other hand over your entire breast to lift it up. Gently push the breast in and up in a way that a good bra cup would when measuring. Use other hand to bring the tape straight down around the curve of your breast until you hit the point where your breast ends, commonly known as your wireline and where your wires would normally sit at the breast root.
This is the horizontal measurement of the breast from the underarm to the center front of the chest. 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. Most of us have a fold on the underarm side of the breast to indicate the area where the breast tissue ends. If you're not wearing a bra, slightly bend over to make this measurement easier. Careful not to indent the breast tissue.
Start measuring tape on top of your shoulder bone and bring it down to where your bra strap would attach to the cup. Bring measurement tape straight down towards your nipple when taking this measurement.Ideal if wearing a bra but not necessary. If you don't have a bra on, measure until just beneath the start of your armpit. Common range is between 5-8 inches.