The key to finding the best nursing bras is to know your exact cup size. Only then will you be able to find the bras that offer you the appropriate amount of support. The easiest way to ascertain your nursing bra size is to have yourself professionally measured. But, if you do not have time to get that done, you may measure yourself.
You will need a soft tape measure or a piece of ribbon or string that you may measure against a ruler or yard stick. When you measure yourself, do so in front of a mirror and wear your best-fitting, unpadded bra.
The first measurement you want to take is a below-the-bust measurement. To do this, you need to measure directly beneath your bust, around your rib cage. The tape measure must be evenly horizontal the entire way around; do not pull the tape too tautly. Next, measure around the fullest part of your bust, and again make sure that the measure tape is completely horizontal. Take down these measurements.
Subtract the below-the-bust measurement from the bust measurement in order to determine your cup size. A size difference of one inch is an A cup, a size different of two inches is a B cup, a size difference of three inches is a C cup, etc. Add the below-the-bust measurement to the bust measurement to get your nursing bra size. For example, if the below-the-bust measurement is 40 inches and you have a D cup, you should purchase a size 40D nursing bra.
Using this information will help you purchase the most supportive nursing bras for you.