1 Measure your chest circumference 2 in (5.1 cm) below your nipples. Place a soft measuring tape against your bare skin or a thin t-shirt, without a bra. Position it directly under your bust area where your bra band will sit, or about 2 in (5.1 cm) below your nipples. Keep the tape positioned horizontally all the way around your body, then make a note of the measurement on the tape.[1]

    *Use a mirror to check that the tape is positioned parallel to the floor as it extends under your arms and across your lower shoulder blades before noting your measurement.
    *Avoid holding your breath since doing so can expand your chest. Exhale to release the air from your lungs and return your ribcage to a natural, non-expanded size.

2 Calculate your band size by adding 4 or 5 to your chest circumference. Round your chest measurement to the nearest whole number. If you ended up with an even number, add 4. If you got an odd number, add 5. The sum will be your bra band size.[2]

    *If you measured 29.5, you’d round up to 30 and add 4 to reach a band size of 34.
    *If your measurement was 33, add 5 to reach a band size of 38.
    *The band size is the first part of a bra size, and it’s followed by a letter indicating the cup size. So a 36C bra and a 36DD bra have the same-sized band, but different cup sizes.

3 Find your natural cup size by measuring directly across your nipples. Extend the tape measure around your chest, keeping it in line with your nipples this time. For people with breasts, this measurement will be larger than the first measurement. Whether yours is smaller, the same, or larger than the first, round this measurement to the nearest whole number. Then subtract this from your chest measurement to determine your cup size.[3]

    *A difference of 0 means you’d wear an AA cup. A difference of 1 means an A cup, 2 means a B cup, 3 means a C cup, 4 means a D cup, 5 means a DD cup, 6 means a DDD or F cup, and 7 means a G cup.[4]
   * If your band size is 34 and your bust also measures 34, you’d wear an AA cup without any padding. So you could purchase a bra in the size 34AA.
   * If your band size is 38 and your bust measures 40, a B cup might fit you best. Try a bra sized 40B if you don’t want to use any padding.

4 Select your ideal bra cup size if you plan to use padding. When picking a cup size, stick with your band size and choose a cup size that’s proportional to your body. If you have a broad chest and shoulders, consider a D or DD cup. If you have a small frame, something like a B or C cup could look flattering. Try out different options until you find the size you love.[5]

    *In bra sizes, subsequent letters indicate larger cup sizes. So, if a 34AA bra would fit your natural, unpadded form, you could go up to a 34B or 34C for a larger cup size.
    *Feel free to try out different cup sizes and breast forms. Just make sure you have the right bra to wear with each one.

5 Consider getting fitted by a bra retailer. If you’re not familiar with bra sizing, a professional bra fitter or bra sales associate can help point you in the right direction. During your fitting, ask them to bring you a variety of different sizes and styles while you’re in the fitting room. This will make the process of finding your perfect size more fun and hassle-free.

    *If you’re nervous about requesting a fitting, consider contacting the shop in advance. Find out whether their staff knows how to assist males with bra fittings, and see if you can make an appointment.[6]