How To Measure Your Bra Size

Did you know that 70% of women are wearing the wrong bra size? It’s true! Finding the right size can be confusing, but it’s essential for both comfort and confidence. Wearing the wrong size can lead to discomfort, poor posture, and an unflattering silhouette.

In this guide, we’ll show you two simple ways to measure your bra size—by using our Bra Size Calculator or following a few easy manual steps. Whichever method you choose, we’re here to help you get the support you need to feel comfortable and confident all day long!

Method 1: Use BOOMBA's Bra Size Calculator

If you'd rather skip the manual steps, try our easy-to-use Bra Size Calculator! All you need to do is input your underbust and overbust measurements, and we'll calculate your perfect bra size for you.

Inches (in)Centimeters (cm)

HOW TO MEASURE YOUR UNDERBUST

BANDin.

HOW TO MEASURE YOUR OVERBUST

BUSTin.

YOUR BOOMBA SIZE:

US = EU = UK = FR/ES = IT = AU/NZ =

RESET

This tool takes out all the guesswork, ensuring that you get the most accurate fit without doing any math. Perfect for those who prefer a quick, reliable answer!

Method 2: Measure Manually at Home

What You Need

Tape measure
The best-fitting non-padded wired bra
Pen and paper to write down your measurements

Step 1: Find Your Band Size

Wrap the tape measure snugly around your rib cage, directly under your bust. Be sure it’s not too tight or too loose. Round this number to the nearest whole number.

If your measurement is even, add 4 inches.
If your measurement is odd, add 5 inches.

Example: If your underbust measurement is 31 inches, add 5 inches, making your band size 36.

Step 2: Measure Your Bust Size

Next, measure around the fullest part of your bust, typically across the nipple line. Keep the tape parallel to the floor, and ensure it rests comfortably on your skin—not too tight, but not too loose either.

Step 3: Calculate Your Cup Size

Subtract your band size (from Step 1) from your bust measurement (from Step 2) to determine the difference. Use the chart below to find your cup size.

Example: If your bust size is 38 inches and your band size is 36 inches, then 38 - 36 = 2. According to the chart, a 2-inch difference means you’re a B cup.

Note that this chart uses US cup sizes.

Now, combine your band size with your cup size. For example, if your band size is 36 and your cup size is B, your bra size is 36B.

How to Choose the Right BOOMBA Size

Now that you know your bra size, selecting the correct size for your BOOMBA inserts is a breeze! Simply refer to our chart below, and don’t forget to size up if you’re in between sizes to ensure the perfect fit with our inserts.

BRA SIZE

US	BOOMBA BRA SIZE
28A	AA
30A	AA
32A	AA
34A	A
36A	B
38A	C
40A	D
42A	E
44A	F

28B	AA
30B	AA
32B	A
34B	B
36B	C
38B	D
40B	E
42B	F
44B	G

28C	AA
30C	A
32C	B
34C	C
36C	D
38C	E
40C	F
42C	G
44C	H

28D	A
30D	B
32D	C
34D	D
36D	E
38D	F
40D	G
42D	H
44D	I

28DD/E	B
30DD/E	C
32DD/E	D
34DD/E	E
36DD/E	F
38DD/E	G
40DD/E	H
42DD/E	I
44DD/E	J

28DDD/F	C
30DDD/F	D
32DDD/F	E
34DDD/F	F
36DDD/F	G
38DDD/F	H
40DDD/F	I
42DDD/F	J
44DDD/F	K

BRA SIZE

US	BOOMBA BRA SIZE
28G	D
30G	E
32G	F
34G	G
36G	H
38G	I
40G	J
42G	K
44G	L

28H	E
30H	F
32H	G
34H	H
36H	I
38H	J
40H	K
42H	L
44H	M

28I	F
30I	G
32I	H
34I	I
36I	J
38I	K
40I	L
42I	M

28J	G
30J	H
32J	I
34J	J
36J	K
38J	L
40J	M

28K	H
30K	I
32K	J
34K	K
36K	L
38K	M

28L	I
30L	J
32L	K
34L	L
36L	M

28M	J
30M	K
32M	L
34M	M

28N	K
30N	L
32N	M

28O	L
30O	M

28P

How to Know If Your Bra Fits Correctly

Once you’ve found your size, it's important to make sure your bra actually fits. Use this checklist to double-check the fit:

Straps: They should rest comfortably on your shoulders without digging in.
Band: It should be snug but comfortable, with enough room to fit two fingers underneath.
Underwire: The underwire should sit flat against your rib cage without poking or lifting away.
Cups: The cups should fully encase your breasts without any spillage on the sides or over the top.

Conclusion

Finding your perfect bra size doesn’t have to be complicated. Whether you prefer using our Bra Size Calculator or measuring manually, we’ve made it easy to discover the right fit. Once you know your size, shopping for bras becomes a lot more fun and less of a hassle!

Ready to shop? Explore BOOMBA products today and find your new favorites. If you need any help, don’t hesitate to reach out via email or DM—we’re always here to assist!

How To Measure Your Bra Size