Quick answer
To find your bra size online, measure your underbust and full bust with a soft tape measure. Subtract the bust from the band measurement to get your cup size. Always check the brand's size chart before ordering.
What you'll need
Grab a soft measuring tape, a mirror, and a non-padded bra (or no bra). Wear the bra you plan to wear most often. Stand straight with your arms relaxed at your sides. Take measurements in inches or centimeters and keep a note of both.
Understanding size charts
Bra sizing varies between brands. A 34C from one label may fit differently from another. Always check the specific brand's size chart before adding to cart. If you fall between sizes, consider sizing up for comfort or down for support.
Common fitting mistakes
Many first-timers measure over a thick bra or pull the tape too tight. The band should be snug but not digging in. The center gore (the part between cups) should lie flat against your chest. If it floats, the cup is likely too small.
Step-by-step guide to measure your bra size
- Measure your band size: Wrap the tape snugly around your ribcage directly under your bust. The tape should be level and tight enough that it won't slip. Round to the nearest whole inch. If the number is even, add 4 inches. If odd, add 5 inches. This is your band size. Common mistake: measuring over clothing or pulling the tape too loose. The band provides 80% of support.
- Measure your bust size: Wrap the tape around the fullest part of your bust, keeping it parallel to the floor. Don't pull tight—let it rest gently. Round to the nearest whole inch. This measurement is your bust size. Checkpoint: stand straight and look straight ahead. Leaning forward can add an inch or more.
- Calculate your cup size: Subtract your band size from your bust size. Each inch of difference equals one cup size: 1 inch = A, 2 inches = B, 3 inches = C, and so on. For example, a 36 band and 38 bust gives a B cup. Common mistake: assuming cup size is absolute. A 34C holds a different volume than a 36C. Always use your band measurement first.
- Double-check with the brand's size chart: Open the brand's size chart and find your band and cup combination. Some brands use sister sizing: if 34C feels tight, try 36B. The cup volume stays the same even though the band changes. Checkpoint: if your measurement falls between two sizes, order both and return the one that doesn't fit.
Products that help you get the right fit
- The Everyday Soft Balcony: The Everyday Soft Balcony is part activewear, part everyday wear. The Tank's built-in bra and our best selling quick-dry Workout fabric makes this your go-to for life errands, Pilates or lounging. If you're new to bra sizing, a versatile style like this lets you test your fit across different activities without buying multiple bras.
The Tank
