Measure around the largest part of your breasts

Measure the area around your chest directly under your arms. This is the band size, which is the number before the letter in the bra's size. Pay attention that the measuring tape is pulled around this area comfortably, not tightly.

Measure around the largest part of your breasts International Costume supplier, which is generally around the nipple. Take this number and subtract your band size from it. The subtracted number will determine your cup size. For instance, if your subtracted number is one inch less, you will wear an "A" cup bra. Two inches translates into a "B" cup, three is a "C" and "D" is five inches.

Put on your most comfortable bra. With the measuring tape, measure around the bra directly under the bust after exhaling---this measurement should be the smallest possible. You can have a friend take down the measurement or hold the measuring tape. Round all fractions up.

Add 4 inches to the under bust measurement if the measurement is even. Add 5 inches if the measurement is odd. For example, if your under bust is 28 inches, your band size is 32 and if it is 27 inches, your band size is also a 32.

Place the tape measure over the fullest part of your bust.

Extend the tape measure around your chest, keeping it level all the way around. Hold the tape measure fairly tight against your bra, without pulling or squishing, which could result in an inaccurate measurement.

Record the measurement in inches, rounding up to the nearest whole number. This is your cup size.

Subtract your band size from your cup measurement. If the two measurements are the same, you should wear an A cup. A difference of one inch indicates a B cup, with each additional inch increasing one letter size, including C, D, DD, DDD/E, F, FF and G. Most department stores and women's clothing shops carry cup sizes up to at least D, while maternity stores, plus-size clothing stores and lingerie shops usually have a broader range of sizes.MORE:Serving Wench Costume supplier