​​​​​One of the most common reasons for breast discomfort and pain is wearing a bra that doesn't fit well. Wearing a bra that is the wrong size can also contribute to back, shoulder, chest, and neck pain. For a bra to give good support and help lessen or prevent breast pain, it needs to fit properly.​

Tips for a good-fitting bra

To make sure your bra fits well and provides good support, make sure:

• The bra is comfortable.
• The back of the bra doesn’t slide up your back.
• The shoulder straps aren't too tight or digging in.
• Your nipple line is midway between your shoulder and elbow.
• Your breasts don’t bulge out above the cups or into your armpits.
• The band isn’t too tight, so you can put your finger under the band easily.
• The centre of the bra fits close to the breast bone (sternum).
• For a bra with underwire, the underwire lies flat against the body and doesn’t dig in.

Measure your cup size

Before measuring your cup size, lean forward and let your breasts fall into the bra cups before you fasten it at the back. Then:

1. Measure your chest (in inches) above the breasts and under the armpit.
2. Measure around the high point of the bust line and compare it to the first measurement.

The difference between the 2 measurements helps you find your cup size:

• no difference or less than 1 inch difference – AA cup
• 1 inch difference – A cup
• 2 inches difference – B cup
• 3 inches difference – C cup
• 4 inches difference – D cup
• 5 inches difference – DD/E cup
• 6 inches difference – DDD/F cup
• 7 inches difference – DDD/G cup
• 8 inches difference – H cup

If your breasts aren’t the same size, always choose the cup size that fits the larger breast, so you have enough room and support. You can use a bra insert in the cup of the smaller breast. You can find bra inserts in most bra stores.

If you still need help to find your cup size, you can go to a store that specializes in fitting bras.

How often to measure

Measure your cup size once a year or when your weight changes, you are pregnant, or you are breastfeeding.

When your measurement changes, it is time to get a new bra.

Sports bras

You might have less pain wearing a bra without underwire or a sports bra.

If breast pain wakes you at night, try wearing a sports bra to bed.

Replace sports bras once they start to lose their elasticity and support.​