Finding a bra that fits perfectly doesn’t have to be complicated—or require a professional fitting. With a soft measuring tape, a few minutes of your time, and a clear step-by-step approach, you can determine your perfect bra size at home with accuracy. This comprehensive guide explains everything you need to know: how to take correct measurements, how to interpret them, how to spot a great fit, and how to choose Commando bras and bralettes designed to move with your body.

A well-fitting bra supports your natural shape, improves posture, and enhances the fit of your clothing. When your bra fits correctly, you’re more comfortable throughout the day, less distracted by adjusting straps or bands, and better supported during movement.

At Commando, our bras—like the Butter™ Soft Support Bralette—are engineered with premium, high-stretch, buttery-soft fabrics that mold to your body. Accurate sizing ensures these performance materials can deliver maximum comfort, flexibility, and support.

• A soft measuring tape

• A thin, non-padded bra (or no bra for more accuracy)

• A mirror to ensure the tape is level

• A place to write down measurements

Wearing a lightweight bra such as the Butter Bralette can help you achieve more accurate measurements.

Stand in front of a mirror. Wrap the measuring tape snugly around your ribcage, directly under your bust. The tape should lie flat and parallel to the floor.

Look at the measurement where the tape meets. Round up or down to the nearest whole inch.

The number you just measured is your band size. If the measurement feels tight with normal breath, that’s correct—your band provides most of your support.

Wrap the measuring tape around the fullest part of your bust. Ensure it’s level across your back and resting comfortably across the tissue.

Don’t pull tight. A relaxed tape helps capture your natural shape.

Subtract your band measurement from your bust measurement:

• 1" difference = A cup

• 2" difference = B cup

• 3" difference = C cup

• 4" difference = D cup

• and so on…

This gives you your cup size, which, when paired with your band, becomes your bra size.

A good band sits straight across the back. It shouldn’t ride up, dig in, or feel loose. If it moves, gaps, or shifts, you need a smaller band.

Your straps should rest comfortably on your shoulders. If they’re digging in, your band may be too big and the straps are compensating for support.

Cups shouldn’t gap, fold, wrinkle, or overflow. If they do, you may need a different size or bra shape.

For a fit-first, flattering silhouette, try the Chic Mesh Plunge Underwire Bra, a design that blends structure with softness.

Solution: Go down one band size.

Solution: Try a smaller cup or a different style.

Size up in the cup.

Solution: Tighten the straps or choose a style with adjustable or closer-set straps.

Solution: You may need a larger cup or a more supportive design.

Butter™ Soft-Support Bralette - An ultra-stretchy, lightweight option ideal for daily wear. Commando’s Butter™ Soft Support Bralette is made from a luxuriously soft Austrian modal blend that is pilling resistant, machine washable, and sustainably sourced. Constructed with molded cup support, removable padding, and raw-cut edges with bonded fusion technology, this bralette has a barely-there look and feel. 

Butter Comfy Bralette - Invisible under clothing, exceptionally soft, and perfect for movement. It’s not called the comfy bralette for nothing. The Butter™ Comfy Bralette is made from our ultra-soft Butter fabric and designed in a longline style for that perfect fit. With molded cups for extra support, this bralette is versatile, chic, and, yes, seriously comfortable.

Chic Mesh Plunge Underwire Bra - Great for lift, shape, and versatile styling. Commando's Chic Mesh Plunge Underwire Bra is constructed from our luxury mesh, with support and comfort in mind. This luxe bra boasts a plunging neckline and an underwire cup, adjustable straps, and hook and eye closure for a customized fit. Available in sizes 32B - 38DD.

Every 6–12 months, or any time you experience weight changes, body changes, pregnancy, or fluctuations in swelling.

Our top pick: The Butter Bralette—stretchy, soft, breathable, and supportive.

Plunge, bralette, balconette, and wireless bras all have unique fits. Trying on a few silhouettes helps you identify your best match and fit.

Finding your correct bra size empowers you to choose styles that feel amazing, last longer, and support your daily life with ease. With the right measurements and the right Commando bras, you’ll enjoy comfort, confidence, and a beautifully smooth foundation under every outfit.