How to Find Your Perfect Bra Size at Home: A Step-by-Step Guide

Quick Answer

To find your bra size at home, you'll need a soft measuring tape and a mirror. Measure your band size by wrapping the tape snugly around your ribcage, then measure your bust at the fullest part. Subtract the band measurement from the bust measurement to determine your cup size. Try on a bra in your calculated size and adjust based on fit and comfort.

Finding the right bra size can feel like a mystery, but you don't need a professional fitting to get it right. With a few simple measurements and some knowledge of how a bra should fit, you can find your perfect size from the comfort of your home. This guide walks you through each step, so you can shop with confidence and enjoy all-day comfort.

At Blue Canoe, we believe that comfort starts with the right fit. Our organic cotton bras are designed to feel soft and supportive, but they only work their magic when you choose the correct size. Whether you're new to measuring or just need a refresher, this step-by-step process will help you get accurate measurements every time.

What You'll Need

Before you start, gather a few essentials: a soft measuring tape (like one used for sewing), a mirror, and a well-fitting, non-padded bra to wear during measurement. If you don't have a soft tape, you can use a piece of string and a ruler. Wear the bra that best represents your usual fit, but avoid ones with heavy padding or push-up effects, as they can distort your natural shape.

Measure yourself at the end of the day when your body is at its normal size, and avoid measuring right after a workout or during your menstrual cycle when breasts may be swollen. Stand straight with your arms relaxed at your sides, and look straight ahead in the mirror to ensure the tape is level.

• Use a soft, flexible measuring tape for accuracy.
• Measure in front of a mirror to ensure the tape is horizontal.
• Wear a non-padded bra for the most accurate bust measurement.

Measuring Your Band Size

Your band size is the number that corresponds to the measurement around your ribcage, just under your bust. Wrap the tape measure snugly around your ribcage, making sure it sits parallel to the floor. It should be tight enough to stay in place but not so tight that it digs into your skin. Take the measurement in inches and round to the nearest whole number.

If the measurement is an even number, add 4 inches to get your band size. If it's odd, add 5 inches. For example, if your underbust measures 30 inches, your band size is 34. This classic method ensures a comfortable yet supportive fit. However, some modern sizing methods skip the addition and use the exact measurement, so it's always good to try on a bra in your calculated size and adjust.

• Common mistake: measuring too loosely, which leads to a band that rides up.
• Checkpoint: The band should sit level across your back and not shift when you move.

Measuring Your Bust Size

Next, measure the fullest part of your bust. Wrap the tape around your back and across the fullest point of your chest, typically at nipple level. Keep the tape parallel to the floor and snug but not tight. Take the measurement in inches and round to the nearest whole number. This is your bust measurement.

Ensure the tape isn't compressing your breast tissue, as that can result in a smaller cup size. If you're between sizes, round up to the nearest whole number. It's also helpful to measure while wearing a non-padded bra, as this gives a more natural contour and prevents overestimation.

• Common mistake: measuring too tightly or too loosely, both skew the cup size.
• Checkpoint: The tape should feel like a gentle hug, not a squeeze.

Calculating Your Cup Size

To determine your cup size, subtract your band measurement (the adjusted number from step 2) from your bust measurement. Each inch of difference corresponds to a cup size: 1 inch = A, 2 inches = B, 3 inches = C, 4 inches = D, and so on. For example, if your band size is 34 and your bust measurement is 37, the 3-inch difference means you're a C cup.

This calculation is a starting point. Different brands and styles may fit differently, so it's essential to try on bras in your calculated size and also in sister sizes (for example, if 34C feels tight, try 36B). Your bra size can also change over time due to weight fluctuations, exercise, or hormonal changes, so remeasure every six months or whenever you notice discomfort.

• Common mistake: relying solely on the calculation without trying on the bra.
• Checkpoint: The center gore (the part between the cups) should lie flat against your sternum.

Trying On and Adjusting

Once you have your measurements, try on a bra in your calculated size. Fasten it on the loosest hook—this allows you to tighten it as the bra stretches over time. Lean forward and scoop your breast tissue into the cups, ensuring the underwire (if present) sits behind the breast tissue and not on it. The band should feel snug but not restrictive, and you should be able to slide two fingers under it.

Check the straps: they should be adjusted to a comfortable tension, providing about 10-20% of the support, with the band providing the rest. The cups should contain your breasts without spillage or gaping. Move around, raise your arms, and bend over to test the bra's stability. If the band rides up in the back, it's too loose; if the straps dig into your shoulders, the band may be too large or the cups too small.

• Common mistake: using the tightest hook right away, which shortens the bra's lifespan.
• Checkpoint: The bra should stay in place when you lift your arms overhead.

Your Step-by-Step Fit Checklist

1. Measure your band: Wrap the tape snugly under your bust, round to the nearest whole number, and add 4-5 inches to get your band size. Checkpoint: The tape should be level and snug, not loose.
2. Measure your bust: Measure around the fullest part of your chest, keeping the tape parallel and comfortable. Checkpoint: Don't pull the tape too tight; it should rest on your skin without compressing.
3. Calculate cup size: Subtract your band size from your bust measurement; each inch equals one cup size (1=A, 2=B, etc.). Checkpoint: Use this as a starting point; sister sizes may fit better.
4. Try on and adjust: Fasten on the loosest hook, scoop tissue into cups, and adjust straps so they don't dig in. Checkpoint: The band should stay level, and the center gore should lie flat.
5. Test movement: Raise your arms, bend, and twist to ensure the bra stays in place and feels comfortable. Checkpoint: If the bra shifts or feels tight, try a sister size or different style.

Blue Canoe Bras for Every Fit

• Bralette: This addition to our almost-famous organic cotton bra collection has a wide, shaped band that is 24-hour comfortable and won't ride up or dig in. The small dart and stretchy fabric give support and shape. If you're between sizes or prefer a wire-free option, this bralette offers flexible sizing and all-day comfort, making it a great choice for lounging or light activity.
• Pointelle V Bra: This style features a gentle V-neck with a slight front crossover, adjustable straps, and a delicate lacy neckline. Comfort, support, and natural beauty — your new favorite bra. With adjustable straps, this bra lets you fine-tune the fit for your unique shape, ensuring support where you need it most while keeping a feminine aesthetic.
• Jane Bra II: Now featuring added pockets designed to hold soft molded cups for enhanced shape and support. The flattering crossover front design provides easy access for nursing and is great for fluctuating breast size. If your size fluctuates due to nursing or hormonal changes, this bra's crossover design and removable cups adapt to your body, offering both support and convenience.

Finding your perfect bra size at home is a straightforward process that empowers you to shop with confidence. By following these steps and remeasuring periodically, you'll ensure a comfortable and supportive fit. At Blue Canoe, our organic cotton bras are designed with your comfort in mind, and with the right size, you'll experience the difference. Explore our collection today and treat yourself to the comfort you deserve.