Bra Size Calculator
Measure at home in two steps. Get your US bra size, your sister sizes and your bralette size, then shop bras in your size at every budget.
What’s my bra size?
1. Measure your band
Snug, right under the bust
- Wear a non-padded bra and stand in front of a mirror.
- Wrap the tape snugly around your ribcage, right under your bust.
- Keep it level, breathe out, and read the exact number.
2. Measure your bust
Loose, at the fullest part
- Wrap the tape around the fullest part of your bust.
- Keep it level across your back.
- It should sit flat without squeezing or leaving a dent.
Every brand fits a little differently. Use this as your starting size and check the brand’s own chart.
Shop bras
How to find your bra size
Measure snugly under your bust and round to the nearest even number: that’s your band. Measure loosely around the fullest part of your bust. Subtract band from bust, and each inch of difference is one cup size, starting at A. A 34 band with a 38-inch bust is 4 inches, so you’re a 34D.
US bra size chart
Find your band on the left, then follow the row to your bust measurement in inches. The column it sits in is your cup.
| Band | A | B | C | D | DD/E | DDD/F | G | H |
|---|---|---|---|---|---|---|---|---|
| 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 |
| 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 |
| 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 |
| 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 |
| 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |
| 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 |
| 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 |
| 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 |
Bust measurements in inches. Cups after D vary by brand: in most US brands DD equals E and DDD equals F.
Get an accurate measurement
- Wear a non-padded or lightly padded bra
- Keep the tape level all the way around
- Breathe normally when you measure
- Remeasure every 6 to 12 months
- Don’t pull the tape too tight on your bust
- Don’t hold your breath
- Don’t add 4 inches to your band (the old method)
- Don’t measure over a padded or push-up bra
What are sister sizes?
Sister sizes hold the same cup volume on a different band. Go one band down and one cup up (34B to 32C), or one band up and one cup down (34B to 36A). Try them when the cups fit but the band feels too tight or too loose.
Signs your bra doesn’t fit
Want a bra that disappears under white tops? See my guide to nude bras for women of color, and the bra mistakes most women make.
Bra size questions
How do I calculate my bra size?
Measure snugly under your bust and round to the nearest even number for your band. Measure loosely around the fullest part of your bust. Each inch of difference is one cup: 1 inch is an A, 2 inches a B, 3 inches a C, 4 inches a D.
Is DD the same as E?
In most US brands, yes. DD and E are the same cup, and DDD is the same as F. UK sizing runs differently after D.
What is 34B in small, medium or large?
A 34B usually fits a Small or Medium in bralettes and sports bras. Letter sizes vary, so check the brand’s chart.
Should I add 4 inches to my band?
No. The add-4 method is outdated and usually gives a band that’s too big. Use your underbust rounded to the nearest even number.
What if I’m between sizes?
Try your calculated size and its sister sizes. Stretchy bralettes and wireless styles are more forgiving if you fall between two sizes.
How often should I measure?
Every 6 to 12 months, and after weight changes, pregnancy or a new workout routine.