A bra size comes from two measurements, and both can be taken in centimetres. The underbust gives the band number. The bust, compared with that band, gives the cup letter. The tables below are in whole centimetres and follow the same arithmetic as our bra size calculator, which accepts cm directly.
Which band is my underbust in cm?
Measure around the ribcage directly under the breasts, tape snug and level, breath let out.
| Underbust (cm) | Band size |
|---|---|
| 56 to 60 | 28 |
| 61 to 66 | 30 |
| 67 to 71 | 32 |
| 72 to 76 | 34 |
| 77 to 81 | 36 |
| 82 to 86 | 38 |
| 87 to 91 | 40 |
| 92 to 96 | 42 |
| 97 to 101 | 44 |
The band number itself is in inches. It is the underbust rounded up to the next even inch, plus four, which is why a 74 cm ribcage wears a 34 and not a 30. What underbust means explains where the four comes from.
Which cup is my bust in cm?
Measure around the fullest part of the bust, tape level, resting on the body without pulling. Find your band's row and read across.
| Band | A | B | C | D | E | F |
|---|---|---|---|---|---|---|
| 28 | up to 73 | 74 to 76 | 77 to 78 | 79 to 81 | 82 to 83 | 84 to 86 |
| 30 | up to 78 | 79 to 81 | 82 to 83 | 84 to 86 | 87 to 88 | 89 to 91 |
| 32 | up to 83 | 84 to 86 | 87 to 88 | 89 to 91 | 92 to 93 | 94 to 96 |
| 34 | up to 88 | 89 to 91 | 92 to 93 | 94 to 96 | 97 to 99 | 100 to 101 |
| 36 | up to 93 | 94 to 96 | 97 to 99 | 100 to 101 | 102 to 104 | 105 to 106 |
| 38 | up to 99 | 100 to 101 | 102 to 104 | 105 to 106 | 107 to 109 | 110 to 111 |
| 40 | up to 104 | 105 to 106 | 107 to 109 | 110 to 111 | 112 to 114 | 115 to 116 |
Each letter is one inch of bust, about 2.5 cm, so the columns are two or three whole centimetres wide. If your number sits at the edge of a column, measure again before you decide, because a tape held slightly off level moves the reading by more than that.
A worked example in cm
Underbust 75 cm, bust 92 cm.
75 falls in the 72 to 76 row, so the band is 34. On the 34 row, 92 falls under C. The size is 34C.
Change the underbust to 80 cm with the same 92 cm bust and the band becomes 36. On the 36 row, 92 is an A. Same bust, different ribcage, and the size moves from 34C to 36A. That is why bust size is not bra size.
32 bra size in cm
A 32 band fits an underbust of 67 to 71 cm.
| Size | Bust (cm) |
|---|---|
| 32A | up to 83 |
| 32B | 84 to 86 |
| 32C | 87 to 88 |
| 32D | 89 to 91 |
More on fit and sister sizes for this band in the 32 bra size guide.
34 bra size in cm
A 34 band fits an underbust of 72 to 76 cm.
| Size | Bust (cm) |
|---|---|
| 34A | up to 88 |
| 34B | 89 to 91 |
| 34C | 92 to 93 |
| 34D | 94 to 96 |
See the 34 bra size guide for the band as a whole.
36 bra size in cm
A 36 band fits an underbust of 77 to 81 cm.
| Size | Bust (cm) |
|---|---|
| 36A | up to 93 |
| 36B | 94 to 96 |
| 36C | 97 to 99 |
| 36D | 100 to 101 |
And the 36 bra size guide for this band.
How do I convert a bra size from inches to cm?
You do not convert the size, only the measurements behind it. A 34C is called a 34C everywhere on Indian sizing, whether you measured in inches or centimetres. To convert a measurement, multiply inches by 2.54 or divide centimetres by 2.54. A 36 inch bust is 91 cm. A 30 inch underbust is 76 cm.
European labels are a separate matter. They print the band in centimetres, such as 75 or 80, and use their own cup letters. That is a different sizing system, and the bra size converter handles it.
Why does this chart differ by a centimetre from others?
Rounding. Charts printed in inches and converted afterwards round each end of each range, and the rounding can land a centimetre either side. The tables here were built the other way round, by running each whole centimetre through the calculator's rule, so they agree with what the calculator will tell you. For the same grid in inches, see the bra size chart for India, and for what each letter means, cup size meaning.
Which sizes do stick-on products use?
The strapless adhesive bra uses band and cup, from 30A to 40D, so both tables above apply. The butterfly stick-on bra and the fabric uplift cups go by cup letter alone. A label that prints DD means the E column here, as the DD cup guide explains.
The short version
Underbust in cm picks the band: 67 to 71 is a 32, 72 to 76 a 34, 77 to 81 a 36. Bust in cm, read on that band's row, picks the cup, and each letter is about 2.5 cm wide. Measure both with the tape level, and if you would rather skip the tables, enter the two numbers in the bra size calculator with centimetres selected.
