How to Find the Cup Size for a Bra

Determining the correct cup size allows a woman to wear an undergarment that enhances her assets while offering needed support. Finding the best fit for a brarequires having accurate measurements. Knowing the cup size before buying prevents hours of trying on different bras in the dressing room to get the best fit. It also enables a woman to order a specially made bra on the Internet.

1) Remove all clothing from the waist up, but keep on your best-fitting bra. Wear the most supportive and comfortable bra owned, but avoid padded bras, as their extra material does not reflect the true measurements of the body.

2) Have a friend stand behind you and wrap the tape measure around the fullest portion of the rib cage, just below the breast. Write this number down in inches. Add 5 inches to it to get the proper band size for a bra. Round up to the next even number should the total be an odd number. This number equals the size for the bra. For instance, if the measurement is 28 inches, add 5 to get 33. Round this up to 34 for the bra strap size.

3) Wrap the tape measure over the breasts and under the arms to determine the bra strap size. Use this alternative method for bra strap size for solo measuring. Do not add anything to this number, but round up to the next even number should the measure equal an odd number. For instance, a measured distance of 35 inches rounds up to 36 inches. Write this number down for the strap size.

4) Wrap the tape measure around the chest at the fullest part of the breasts. Be sure to wear an unpadded bra or nothing at all. Write this measurement down and subtract the bra strap number from it. Use either the bra strap measurement determined in step two or step three--those numbers should be the same.

5) Take the number from step four to determine the bra cup size. A difference of less than 1 inch equals a AA cup size. Find the appropriate cup size based on the number: 1 inch is A, 2 inches for B, 3 inches for C, 4 inches for D, 5 inches for E and 6 inches for F. Purchase a bra based on the bra strap size and the cup size. Use straps on the bra to adjust for the best support and fit.