How to Find Your Bra Size at Home Before Buying Online
By On Gossamer | Published: 2026-10-14
Category: Guide pratiche
Learn how to find your bra size at home with a tape measure and a few simple steps. Get accurate band and cup measurements to shop online with confidence.
Quick answer
To find your bra size at home, wear an unpadded bra, wrap a soft tape measure snugly around your ribcage just under your bust for the band size, then measure around the fullest part of your bust for the cup size. Subtract the band from the bust measurement to find your cup letter. Always check the brand's specific size chart before ordering online, as sizing can vary.
Why measuring at home beats guessing
Guessing your size leads to band ride-up, cup spillage, or straps that dig in. A five-minute measurement session gives you a reliable starting point, so you can shop online with far less trial and error. Even if you already wear a bra daily, your size can shift with weight changes, hormonal cycles, or a new exercise routine. Re-measuring every six months keeps your fit on track.
What you need before you start
You don't need a professional fitting. A soft, flexible tape measure, a mirror, and a well-fitting unpadded bra are enough. If you don't have a tape measure, use a piece of string and later measure it against a ruler. Wear the bra you plan to wear under clothes, not a sports bra or a push-up style, because those can distort your bust measurement.
How to measure your band size
Stand straight and wrap the tape around your ribcage, directly under your bust. The tape should be snug and level all the way around, parallel to the floor. Breathe normally and exhale before you read the number. If the measurement is an even number, that's your band size; if it's odd, round down to the nearest even number. For example, a 33-inch measurement becomes a 32 band. Write it down.
How to measure your cup size
Wrap the tape around the fullest part of your bust, usually at nipple level. Keep the tape loose enough that it doesn't compress breast tissue, but snug enough that it stays in place. Make sure the tape is straight across your back. Subtract your band measurement from this bust measurement. Each inch of difference equals one cup size: 1 inch = A, 2 = B, 3 = C, 4 = D, 5 = DD, and so on. For example, a 34 band with a 37 bust gives a 3-inch difference, so you're a 34C.
Check the brand's size chart before you buy
Your at-home measurement is a starting point, but brands sometimes use different grading. Always open the size chart on the product page and compare your band and cup numbers to that specific brand's chart. Pay attention to sister sizes: if your calculated size is out of stock, you can often size down in the band and up in the cup (or vice versa) for a similar fit. For example, a 34C is a sister size to a 32D and a 36B.
Your step-by-step bra sizing routine
- Step 1: Put on an unpadded bra: Wear a comfortable, non-push-up bra that fits you reasonably well. Avoid sports bras or heavily padded styles because they change your bust shape. Checkpoint: The bra should not compress your breasts or have empty space in the cups.
- Step 2: Measure your band: Wrap the tape snugly around your ribcage, directly under your bust. Keep it level and parallel to the floor. Exhale and read the number. Common mistake: Measuring too high or too low. The tape should sit exactly where the bra band would rest.
- Step 3: Measure your bust: Wrap the tape around the fullest part of your bust, usually at nipple level. Keep it straight across your back and don't pull it tight. Checkpoint: The tape should touch your skin without indenting it.
- Step 4: Calculate your cup size: Subtract your band measurement from your bust measurement. Each inch of difference equals one cup size: 1 inch = A, 2 = B, 3 = C, 4 = D, 5 = DD. Common mistake: Rounding up the band before subtracting. Always use the exact bust measurement minus the exact band measurement first.
- Step 5: Verify with the brand's size chart: Before ordering online, check the specific brand's size chart. Sizing can vary between brands and styles. Look for sister sizes if your size is unavailable. Next step: If you're between sizes, choose the larger band and smaller cup for comfort, or the smaller band and larger cup for more support.
Products that make sizing easier
- Next to Nothing Micro T Shirt Bra - Champagne: Next to Nothing Micro T Shirt Bra in Champagne features 4-way stretch and lightweight microfiber. The flexible fabric accommodates small measurement variations, making it more forgiving if your size falls between two cup letters.
- Next to Nothing Micro T Shirt Bra - Mauve Chalk: Next to Nothing Micro T Shirt Bra in Mauve Chalk is made from 74% nylon and 26% elastane. The high elastane content provides stretch and recovery, so the bra holds its shape and adapts to your body over time.
- Cabana Cotton Convertible T Shirt Bra - Black: Cabana Cotton Convertible T Shirt Bra in Black has a clean finish, 2-ply wings for smooth, seamless support. The 2-ply wings offer a more structured fit, which can help if you prefer a bit more support around the band.
