Bra Size Chart: How to Measure and Convert Bra Sizes
Work out a bra size from two tape measurements, convert it between US, UK, European, French, Italian and Australian labels, and find the sister sizes to try when the band or cup is off.
A bra size has two parts. The band is your snug underbust measurement, rounded to an even number of inches (34, 36). The cup is the difference between your bust and the band: 1 in = A, 2 in = B, 3 in = C, 4 in = D, 5 in = DD. A 34 in band with a 37 in bust is a 34C, which is 75C in EU sizes.
- One cup size
- 1 in (2.5 cm) of bust
- One band size
- 2 in (5 cm)
- 34C in EU / FR
- 75C / 90C
- Sister sizes of 34C
- 32D, 36B
On this page
How to measure your bra size
You need a soft tape measure and a well-fitting unpadded bra, or no bra. Keep the tape level all the way round; a tape that rises at the back gives a smaller number.
- Band: wrap the tape snugly around your ribcage directly under the bust, exhale, and read the measurement. Round to the nearest even number of inches: 29 → 30, 33.5 → 34. (In cm, round to the nearest 5 cm for the EU band.)
- Bust: measure loosely around the fullest part of the bust, standing straight. Do not pull the tape tight. Some fitters also take this leaning forward at 90 degrees, which captures breast tissue better for fuller or softer busts; use the larger number.
- Cup: subtract the band size from the bust measurement. Each inch is one cup: 1 = A, 2 = B, 3 = C, 4 = D, 5 = DD, then by the letter sequence below.
- Check the result in a fitting. Brands, styles and breast shape all shift the size. The measurement gives a starting point and the fit checks below confirm it.
Older US charts add 4 in to an even underbust (5 to an odd one) to get the band. That gives a band two sizes larger and a cup two letters smaller: an underbust of 30 in and bust of 36 in becomes 34B instead of 30E (UK) or 30DDD (US), which holds two cup sizes more volume. Bra bands are elastic, so most specialist fitters now start from the underbust itself. A 2012 study by White and Scurr at the University of Portsmouth recommended exactly that, after finding that most women in its sample wore bands that were too big and cups that were too small. Brand charts still differ, so read which method a chart uses.
Bra size chart (US cup sizes, bust in inches)
Find your band in the first column and your bust measurement in the row. The column heading is your cup.
| Band | A | B | C | D | DD | 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 |
Half-inch results go to the nearer cup; a 37.5 in bust on a 34 band falls between C and D, and the try-on decides. For example, a 32 band with a 36 in bust is 32D, and a 36 band with a 39 in bust is 36C.
Cup sizes: US, UK and EU letters
US and UK cups match up to DD. After that the UK adds double letters (FF, GG) and the US either repeats D (DDD) or skips straight to later letters, so the same letter can mean different volumes. European cups step every 2 cm instead of every inch, so they pull ahead from about D.
| Difference | US | UK | EU |
|---|---|---|---|
| 0-½ in | AA | AA | AA |
| 1 in | A | A | A |
| 2 in | B | B | B |
| 3 in | C | C | C |
| 4 in | D | D | D |
| 5 in | DD (E) | DD | E |
| 6 in | DDD (F) | E | F |
| 7 in | G | F | G |
| 8 in | H | FF | H |
| 9 in | I | G | varies by brand |
| 10 in | J | GG | varies by brand |
The practical consequence: a US G is a UK F, and a UK G is a US I. When you buy a British brand in the US, use the UK letters.
Bra size conversion: band sizes by country
Bands convert on a fixed ladder: every 2 in on the US/UK scale is 5 cm on the European scales. Cups convert by the letter table above.
| US / UK | EU (DE, NL, Nordic) | FR / ES / BE | IT | AU / NZ |
|---|---|---|---|---|
| 28 | 60 | 75 | 0 | 6 |
| 30 | 65 | 80 | 1 | 8 |
| 32 | 70 | 85 | 2 | 10 |
| 34 | 75 | 90 | 3 | 12 |
| 36 | 80 | 95 | 4 | 14 |
| 38 | 85 | 100 | 5 | 16 |
| 40 | 90 | 105 | 6 | 18 |
| 42 | 95 | 110 | 7 | 20 |
| 44 | 100 | 115 | 8 | 22 |
French, Spanish and Belgian bands are always 15 higher than the EU number, which is why "95C" can mean a US 42C (EU label) or a US 36C (French label). Italian bands are often written in Roman numerals (III = 3). Japan uses EU-style bands but writes the cup first, as in C75.
Measuring in centimeters (EU method)
The European system (EN 13402) works entirely from body measurements in cm: the band is the underbust rounded to 5 cm and the cup is the bust minus the underbust, in 2 cm steps.
| Cup | AA | A | B | C | D | E | F | G | H |
|---|---|---|---|---|---|---|---|---|---|
| Difference (cm) | 10-12 | 12-14 | 14-16 | 16-18 | 18-20 | 20-22 | 22-24 | 24-26 | 26-28 |
Example: underbust 76 cm and bust 93 cm. The band rounds to 75 and the difference is 17 cm, so the size is 75C (US/UK 34C on the conversion ladder). Note that the EU method measures the cup from the underbust, so it gives the same result as the add-4 inch method, not the underbust-only inch method.
Sister sizes
A cup letter is relative to its band: a 32D cup holds about the same volume as a 34C or 36B. If the cups fit but the band is wrong, move to a sister size rather than changing everything.
| Band down, cup up | Your size | Band up, cup down |
|---|---|---|
| 30D | 32C | 34B |
| 32D | 34C | 36B |
| 34D | 36C | 38B |
| 34DD | 36D | 38C |
| 36DD | 38D | 40C |
| 40D | 42C | 44B |
- Band rides up or loose on the tightest hook: go down a band and up a cup (34C → 32D).
- Band digs in but cups fit: go up a band and down a cup (34C → 36B).
- Cups gape or wrinkle with a good band: go down a cup only (34C → 34B), or try a different cup shape.
- Breast tissue spills over the top or sides: go up a cup only (34C → 34D).
Fit checks for a new bra
- Band: level all the way round and snug on the loosest hook, so you can tighten it as the elastic relaxes. You should fit about two fingers under the back band, no more. The band, not the straps, carries most of the support.
- Underwire: sits flat against the ribcage behind the breast tissue, not on it, and the center panel (gore) touches the sternum in most styles.
- Cups: smooth with no gap at the top edge and no spillover at the top or under the arm.
- Straps: stay put without digging in. If you have to tighten them hard, the band is probably too loose.
Bras without underwire size differently: see the bralette size chart for S-XL sizing, the sports bra size guide for impact and compression fit, and the nursing bra size guide for sizing through pregnancy and breastfeeding. Matching briefs are covered in the underwear size chart, and swim tops that use cup sizing in the swimsuit size guide.
Frequently asked questions
What is a 95C bra in US sizes?
It depends on the label. A European 95C is a US/UK 42C. A French or Spanish 95C uses bands 15 cm larger, so it equals EU 80C and US/UK 36C. Check whether the brand is French before converting.
What is a 42C bra in other sizes?
42C is EU 95C, FR/ES/BE 110C, IT 7C and AU 20C. Its sister sizes are 40D (smaller band) and 44B (larger band). The bust measures about 45 in (114 cm).
Is 34C an average bra size?
34C is a mid-range size, not a standard or ideal one. It describes a band of about 34 in and a bust about 3 in larger. Many women measured by the underbust method end up in a smaller band and larger cup than they expected, so a 34C label can cover very different bodies.
My band is 34 and my bust is 42. What is my bra size?
The difference is 8 in, which is a 34H in US labels and 34FF in UK labels (EU 75H). If that cup feels too big, try the sister size 36G (US) or 36F (UK), which has the same cup volume on a larger band.
What size are small-cup bras in UK letters?
UK small cups are AA (bust 0-1 in over the band) and A (about 1 in). Below AA some brands sell AAA. UK and US letters are the same up to DD.
How do I measure my bra size in cm?
Measure the snug underbust and round to the nearest 5 cm for the EU band (73-77 cm = 75). Subtract the underbust from the full bust: 12-14 cm is A, 14-16 cm B, 16-18 cm C, 18-20 cm D, with 2 cm for each further cup.