UK bra size chart

Every UK band from 28 to 56 and every cup from AA to LL, in inches and centimetres. The figures are generated from the same sizing rules as our calculator.

How to read this chart

A UK bra size has two parts: a band number and a cup letter. The band comes from your snug underbust. The cup comes from the difference between your bust measurement and your band, one cup letter for each inch.

  1. Find your band in the band chart, using your snug underbust: measured firmly, directly under your breasts, breathing out.
  2. Take your bust measurement (the larger of your standing and leaning bust) and subtract your band.
  3. Look up the difference in the cup chart. For example, a 32 band with a 36-inch bust is a difference of 4 inches, which is a D cup: 32D.

Or use the full size chart: find your band’s row, move along to the number closest to your bust measurement, and read the cup at the top of that column. Not sure how to take the measurements? See how to measure your bra size.

The charts use whole inches. Real measurements rarely are, so the calculator rounds the difference to the nearest inch, and when it falls 0.4 to 0.6 of the way to the next inch it shows both neighbouring cups.

Cup size chart

Subtract your band from your bust measurement, then find the difference below. Centimetre figures are converted from inches and rounded to one decimal place. A difference of zero or less is shown as AA.

UK cup size for each difference between bust and band
Bust Minus Band (inches)Bust Minus Band (cm)UK Cup
00.0AA
12.5A
25.1B
37.6C
410.2D
512.7DD
615.2E
717.8F
820.3FF
922.9G
1025.4GG
1127.9H
1230.5HH
1333.0J
1435.6JJ
1538.1K
1640.6KK
1743.2L
1845.7LL

Band size chart

Find your snug underbust in whole inches. The modern band is the one our calculator recommends; the traditional band is shown so you can compare it with older size charts.

Modern and traditional UK band size for each snug underbust measurement
Snug Underbust (inches)Snug Underbust (cm)Modern BandTraditional Band
2666.026* (outside the 28–56 range)30
2768.626* (outside the 28–56 range) or 2832
2871.12832
2973.728 or 3034
3076.23034
3178.730 or 3236
3281.33236
3383.832 or 3438
3486.43438
3588.934 or 3640
3691.43640
3794.036 or 3842
3896.53842
3999.138 or 4044
40101.64044
41104.140 or 4246
42106.74246
43109.242 or 4448
44111.84448
45114.344 or 4650
46116.84650
47119.446 or 4852
48121.94852
49124.548 or 5054
50127.05054
51129.550 or 5256
52132.15256
53134.652 or 5458* (outside the 28–56 range)
54137.25458* (outside the 28–56 range)
55139.754 or 5660* (outside the 28–56 range)
56142.25660* (outside the 28–56 range)
57144.856 or 58* (outside the 28–56 range)62*

Odd underbust measurements. A snug underbust of exactly 31 inches sits halfway between the 30 and 32 bands, so the calculator uses your loose underbust to decide. If your loose underbust is at least 3 inches larger than your snug underbust, soft tissue is compressing under the tape and the calculator chooses the smaller, firmer band (30). Otherwise it chooses the larger band (32).

Measurements between whole inches round to the nearest even band: 30.75 inches gives a 30 band and 31.25 inches gives a 32 band.

* Outside the 28–56 range most UK retailers stock. The calculator shows a 28 or 56 band instead, with the cup adjusted to keep the same volume, and explains where to look for other sizes.

Full size chart in inches

Each cell is the bust measurement, in inches, for that band and cup. Scroll sideways to see every cup; the band column stays in view.

Bust measurement in inches for every UK size from 28AA to 56LL. Rows are bands, columns are cups.
BandAAABCDDDEFFFGGGHHHJJJKKKLLL
2828293031323334353637383940414243444546
3030313233343536373839404142434445464748
3232333435363738394041424344454647484950
3434353637383940414243444546474849505152
3636373839404142434445464748495051525354
3838394041424344454647484950515253545556
4040414243444546474849505152535455565758
4242434445464748495051525354555657585960
4444454647484950515253545556575859606162
4646474849505152535455565758596061626364
4848495051525354555657585960616263646566
5050515253545556575859606162636465666768
5252535455565758596061626364656667686970
5454555657585960616263646566676869707172
5656575859606162636465666768697071727374

Full size chart in centimetres

The same chart converted to centimetres and rounded to one decimal place.

Bust measurement in centimetres for every UK size from 28AA to 56LL. Rows are bands, columns are cups.
BandAAABCDDDEFFFGGGHHHJJJKKKLLL
2871.173.776.278.781.383.886.488.991.494.096.599.1101.6104.1106.7109.2111.8114.3116.8
3076.278.781.383.886.488.991.494.096.599.1101.6104.1106.7109.2111.8114.3116.8119.4121.9
3281.383.886.488.991.494.096.599.1101.6104.1106.7109.2111.8114.3116.8119.4121.9124.5127.0
3486.488.991.494.096.599.1101.6104.1106.7109.2111.8114.3116.8119.4121.9124.5127.0129.5132.1
3691.494.096.599.1101.6104.1106.7109.2111.8114.3116.8119.4121.9124.5127.0129.5132.1134.6137.2
3896.599.1101.6104.1106.7109.2111.8114.3116.8119.4121.9124.5127.0129.5132.1134.6137.2139.7142.2
40101.6104.1106.7109.2111.8114.3116.8119.4121.9124.5127.0129.5132.1134.6137.2139.7142.2144.8147.3
42106.7109.2111.8114.3116.8119.4121.9124.5127.0129.5132.1134.6137.2139.7142.2144.8147.3149.9152.4
44111.8114.3116.8119.4121.9124.5127.0129.5132.1134.6137.2139.7142.2144.8147.3149.9152.4154.9157.5
46116.8119.4121.9124.5127.0129.5132.1134.6137.2139.7142.2144.8147.3149.9152.4154.9157.5160.0162.6
48121.9124.5127.0129.5132.1134.6137.2139.7142.2144.8147.3149.9152.4154.9157.5160.0162.6165.1167.6
50127.0129.5132.1134.6137.2139.7142.2144.8147.3149.9152.4154.9157.5160.0162.6165.1167.6170.2172.7
52132.1134.6137.2139.7142.2144.8147.3149.9152.4154.9157.5160.0162.6165.1167.6170.2172.7175.3177.8
54137.2139.7142.2144.8147.3149.9152.4154.9157.5160.0162.6165.1167.6170.2172.7175.3177.8180.3182.9
56142.2144.8147.3149.9152.4154.9157.5160.0162.6165.1167.6170.2172.7175.3177.8180.3182.9185.4188.0

Why the calculator gives a better starting point

A chart can only look up one underbust and one bust number. The calculator does more with the same tape:

  • It uses four measurements. The loose underbust decides between two bands when your snug underbust is exactly odd, and the leaning bust picks up tissue a standing measurement can miss.
  • It handles in-between results. When your bust measurement sits midway between two cups, it shows both rather than quietly rounding one way.
  • It checks your measurements against each other. A confidence score flags results that look inconsistent, such as measuring over a padded bra or a standing bust much larger than your leaning bust.
  • It shows both band methods and your sister sizes, so you have more than one size to try.

Use the calculator. It runs in your browser, so your measurements never leave your device.

Sister sizes

Cup letters are relative to the band, so a D cup on a 32 band holds less than a D cup on a larger band. Sizes that share a cup volume are called sister sizes: one band smaller and one cup letter larger, or one band larger and one cup letter smaller. The closest sister sizes of 32D are 30DD and 34C.

Sister sizes are useful when the cups fit but the band doesn’t. Our guide to sister sizes explains when to try one, and the sister size calculator lists them for any size.

Modern and traditional bands

This chart recommends the modern method: your snug underbust rounded to the nearest even inch. The traditional method rounds to the nearest whole inch and then adds 4 if it is even or 5 if it is odd. You may still see it on older size charts.

The traditional method gives a bigger band and a smaller cup letter from the same measurements. With a 30-inch snug underbust and a 36-inch bust, the modern method gives 30E and the traditional method gives 34B. Our methodology page explains both in full.

Frequently asked questions

UK bands 28 to 56 and cups AA to LL: 285 sizes in all, from 28AA to 56LL.

If your measurements work out at a band outside that range, the calculator shows a 28 or 56 band with the cup adjusted to keep the same volume, and points you to specialist ranges.

UK sizing adds double letters to the cup ladder: DD, FF, GG, HH, JJ, KK and LL. Each letter, single or double, is still one inch of difference between bust and band, so DD is one cup larger than D and one cup smaller than E. The UK ladder has no I cup: it goes from HH to J.

With the modern method, roughly. The band is your snug underbust rounded to the nearest even inch, so a 34 band suits a snug underbust of about 33 to 35 inches.

With the traditional method, a 34 band comes from a snug underbust of 29 or 30 inches, because 4 or 5 inches are added first

Yes. The centimetre tables are converted from inches, because UK cup sizes are defined as one cup per inch, which is 2.54 cm. That is why the centimetre figures are not round numbers. The calculator accepts either unit and gives the same result.

Your usual size may come from the traditional method, which adds 4 or 5 inches to the underbust and gives a bigger band and a smaller cup letter. Sizing also varies between brands and styles, and breast shape affects how a cup fits.

Treat any chart as a starting point and check how the bra itself fits. Our guide to why your bra size feels wrong covers the common reasons.

Related

Sister Size Calculator

Every size with the same cup volume, and when to try each.

Bra Size Converter

UK, US, EU, FR, and AU sizes side by side.
.

Bra size calculator

Four measurements, both band methods, sister sizes and a confidence score.

How UK bra sizes work

What the number and the letters mean.

Sophie Dixon

Sophie Dixon

Hi, I’m Sophie Dixon, the creator of UK Bra Size Calculator. I built this tool because I was tired of seeing women guess their bra size from outdated charts that rarely fit right. I researched UK bra fitting standards and measurement methods in depth so I could offer both the modern and traditional sizing approaches side by side – giving you an honest comparison instead of a single guess. Everything runs privately in your browser, and I’m always refining the calculator to make it more accurate.