DIY Bra Sizing

STEP 1: MEASURE YOUR BAND SIZE

Wrap your measuring tape around your body at your under bust, making sure the tape is parallel with the ground and isn't loose or binding. Exhale completely to get the smallest band measurement possible.

If your band size exceeds 38", band size should be the closest higher even number to your actual measurement. For example, a 41" measurement would be a 42" band size.

STEP 2: MEASURE YOUR CUP SIZE

While wearing a non-padded bra, stand up straight with your arms at your sides. Measure at the fullest part of your bust, making sure the measuring tape is parallel with the ground and not tight or binding. Round all fractional measurements to the nearest whole number.

STEP 3: CALCULATE YOUR BRA SIZE

Subtract your band size measurement (step 1) from your cup size measurement (step 2). Generally, for each inch difference, the cup goes up by one size. Here's an example:

Step 1: 34" under measurement = 36" band size
Step 2: 39" around bust measurement
Step 3: 39" - 36" = 3" or C cup size
Your size: 36C

Note: The cup size calculation starts falling apart at 4 inches larger than your band size. If you have pendulous breasts, your measurement will not be accurate.

Need more details? We've got you covered.

A bra size is made up of two measurement components: band size (34, 36, 38, etc.) and cup size (A, B, C, etc.).

To find your correct bra size, begin by wearing your best fitting unpadded bra (not a minimizer or sports bra). If you are sagging in your bra, tighten the straps until the crest of your breasts is approximately halfway between your shoulder and your elbow. If possible, have someone else take your measurements. Not only is it faster, but it also tends to be more accurate.

Measuring your band size

Option 1:

1. Holding the measuring tape, measure around your bra directly under your bust after expelling all the air from your lungs. You want this measurement to be as small as possible. Look in a mirror to assure the measuring tape is parallel to the floor. The placement of the measuring tape is critical. If it's too high, your measurement will be too large. If it's too low, it will be too small.
2. Round to the nearest inch. For example, if your measurement is 29 3/8", round to 29". If your measurement is 29 1/2" or more, round to 30".
3. If the rounded measurement you come up with is an even number, add 4 inches. If the rounded measurement you come up with is an odd number, add 5 inches.
4. The result is your band size. Example: 33" + 5" = 38" band size.

Option 2:

1. Measure around your body, straight across your back and chest directly above the bust at the underarm level.
2. Stand up straight with your arms at your side and exhale completely. If you're high-busted or have implants, you will have trouble keeping the measuring tape parallel to the floor - but do your best. If your measurement is an odd number, add one inch and the result will be your band size.

If your measurement is:	27	28	29	30	31	32	33	34	35	36	37	38
Then your band size is:	30	30	32	32	34	34	36	36	38	38	38	38

If your measurement is higher than a 38" band size, round up to the nearest even number. For example, 41.5" is a 42 band size and 41" is also a 42 band size.

Measuring your cup size

1. Standing straight with your arms at your sides, measure around your body at the fullest part of your bust while keeping the measuring tape parallel with the floor. Wear an unpadded bra that isn't a minimizer. Make sure the apex of your breasts are halfway between your shoulder and your elbow.

Note for D cup sizes or larger: If your best fitting bra is too tight around your bust, you can also take this measurement without a bra. Hold your breasts up with your hands to where you think they should be. Have someone else then measure around your fullest part.
2. Wrap the measuring tape around you so that it is just touching and not binding. If one of your breasts is significantly larger, put some type of padding in the cup of the smaller breast to make it even with the larger breast before taking your measurement.
3. Round up or down to the nearest inch as you did to find your band size.
4. Subtract your band size measurement from this second measurement. The difference is your cup size.

Example: 38" - 34" (band size) = 4" = D cup size. The chart below shows you how to determine cup size.

The difference	USA cup size*	UK cup size	European cup size	French cup size	Italian cup size	Australian cup size	Japanese cup size	UCS®
0" to 1/2" 0 - 1.3 cm	AA	AA	AA	AA	-	-	A
1/2"- 1" 1.3 - 2.6 cm	A	A	A	A	A	A	B
2" 5.1 cm	B	B	B	B	B	B	C
3" 7.6 cm	C	C	C	C	C	C	D
4" 10.2 cm	D	D	D	D	D	D	E	D1
5" 12.7 cm	DD * or E *	DD	E	E	DD	DD	F	D2
6" 15.2 cm	DDD * or F *	E	F	F	E	E	G	D3
7" 17.8 cm	DDDD * or G *	F	G	G	F	F	H	D4
8" 20.3 cm	H *	FF	H	H	FF	FF	I	D5
9" 22.9 cm	I *	G	J	J	G	G	J	D6
10" 25.4 cm	J *	GG	K	K	GG	GG	K	D7
11" 27.9 cm	K *	H	L	L	H	H	L	D8
12" 30.5 cm	L *	HH	M	M	HH	H	M	D9
13" 35.5 cm	M *	J	N	N	J	J	N	D10
14" 38.1 cm	N *	JJ	O	O	JJ	JJ	O	D11
15" 40.6 cm	O *	K	P	P	K	K	P	D12

*If you're larger than a D cup, use HerRoom's Universal Cup Sizing™ (UCS®) System to find the right cup size for every brand, every time.

For a detailed video on how to measure your bra size, visit the Bra Sizing Calculator.

Measuring yourself for your bra size

Get out the measuring tape!