How to Measure Underband Size
- Use a measuring tape to measure around your ribcage, directly under your bust (along the bottom of where the band would sit).
- Get the measurement from the tape, in centimeters. Then use the underband chart below to find your underband size.
Underband Measurement Chart
CM |
Back band |
58 - 62 |
28 |
63 - 67 |
30 |
68 - 72 |
32 |
73 - 77 |
34 |
78 - 82 |
36 |
83 - 87 |
38 |
88 - 92 |
40 |
How to Measure Cup Size
- Take one of your current bras and look at the underband size marked on the label.
- If the new measurement you just got is smaller than the current underband size, you'll probably have to go up a cup size to get the right fit.
- If your new measurement is bigger than your current underband size, you'll likely need to go down a cup size.
- If your new measurement is the same as your current underband size, but your cups aren't fitting right, you'll need to go up or down one cup size, depending on the fit.
HOW TO MEASURE YOUR BRA SIZE AT HOME

BRA MEASURING GUIDE
To measure your bra size at home, you will need a soft tape measure (alternatively something like a piece of string can be used, alongside a ruler), a mirror, and somewhere to note down the measurements you take. We advise going braless or wearing a non-padded bra whilst measuring, for the most accurate results.
STEP ONE: TAKE YOUR BRA BAND MEASUREMENT
First, you need to find your band measurement. To do this, wrap the measuring tape around your ribs, directly under your bust, where the bra band sits. Keep the tape level and snug as you wrap it around your back - be careful not to wrap it too tight though, you want a comfortably fitting bra after all.

Take your measurement in inches, rounded up to the nearest whole number. If the number you get is odd, round up to the nearest even number - that is your bra band measurement. If you have measured in cm rather than inches, you can use the conversion chart below to work out your band size.
STEP TWO: HOW TO MEASURE YOUR BUST
Next, you’ll need to take the measurement of your bust; this will help you work out your correct cup size in the next step. To measure your bust, wrap the measuring tape around you, over the fullest part of your bust, which will likely be in line with your nipples. Don’t pull the tape too tight when taking this measurement, it can be done loosely. Take the measurement in inches and round it to the nearest whole number.

STEP THREE: HOW TO WORK OUT YOUR CUP SIZE
Now you have your band measurement and bust measurement, it’s time to work out your cup size. Doing this requires a bit of maths, and our conversion table below. You will want to subtract your band inches measurement from the inches of your bust to get the total difference in inches. You’ll use this to work out your cup size.
Bust Size - Band Size = Cup Size
E.g. Bust Size 39 inches - Band Size 34 inches = 5 inches difference = DD Cup Size. Use the table below to work out your cup size using the ‘difference’ figure you get.

Once you have both your band size and cup size, voila you have your bra size and it’s time to start trying some new perfectly fitting bras out.