How to Measure Your Bra Size: A Step-By-Step Guide

April 26, 2023

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.

Measure Your Bra Size

Not sure about your BOOMBA size? Enter your measurements below to find your perfect fit!

Select measurement
Underbust size
Overbust size
Grab a tape measure

How to get your overbust & underbust Size?

  1. Overbust Size. Measure around the fullest part of your bust with a bra on, keeping the tape straight.
  2. Underbust Size. Measure snugly around your ribcage, just under your bust, keeping the tape straight.

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.

● Example: If your underbust measurement is 31 inches, add 1 inch to determine your band size.

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 32 inches, then 38 - 32 = 6. According to the chart, a 6-inch difference means you’re a DDD/F cup.

DIFFERENCE (INCHES)

CUP SIZE

less than 1

AA

1

A

2

B

3

C

4

D

5

E

6

F

7

G

8

H

9

I

10

J

11

K

12

L

13

M

14

N

15

O

16

P

17

R

18

S

Note that this chart uses US cup sizes.

Now, combine your band size with your cup size. For example, if your band size is 32 and your cup size is DDD/F, your bra size is 32DDD/F.

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

A Cups

AU Size

BOOMBA Bra Size

Size Category

6A

AA

X-Small

8A

AA

X-Small

10A

AA

X-Small

12A

A

X-Small

14A

B

Small

16A

C

Small

18A

D

Medium

20A

E

Medium

22A

F

Medium

B Cups

AU Size

BOOMBA Bra Size

Size Category

6B

AA

X-Small

8B

AA

X-Small

10B

A

X-Small

12B

B

Small

14B

C

Small

16B

D

Medium

18B

E

Medium

20B

F

Medium

22B

G

Large

C Cups

AU Size

BOOMBA Bra Size

Size Category

6C

AA

X-Small

8C

A

X-Small

10C

B

Small

12C

C

Small

14C

D

Medium

16C

E

Medium

18C

F

Medium

20C

G

Large

22C

H

Large

D Cups

AU Size

BOOMBA Bra Size

Size Category

6D

A

X-Small

8D

B

Small

10D

C

Small

12D

D

Medium

14D

E

Medium

16D

F

Medium

18D

G

Large

20D

H

Large

22D

I

Large

E Cups

AU Size

BOOMBA Bra Size

Size Category

6E

B

Small

8E

C

Small

10E

D

Medium

12E

E

Medium

14E

F

Medium

16E

G

Large

18E

H

Large

20E

I

Large

22E

J

X-Large

F Cups

AU Size

BOOMBA Bra Size

Size Category

6F

C

Small

8F

D

Medium

10F

E

Medium

12F

F

Medium

14F

G

Large

16F

H

Large

18F

I

Large

20F

J

X-Large

22F

K

X-Large

G Cups

AU Size

BOOMBA Bra Size

Size Category

6G

D

Medium

8G

E

Medium

10G

F

Medium

12G

G

Large

14G

H

Large

16G

I

Large

18G

J

X-Large

20G

K

X-Large

22G

L

X-Large

H Cups

AU Size

BOOMBA Bra Size

Size Category

6H

E

Medium

8H

F

Medium

10H

G

Large

12H

H

Large

14H

I

Large

16H

J

X-Large

18H

K

X-Large

20H

L

X-Large

22H

M

X-Large

I Cups

AU Size

BOOMBA Bra Size

Size Category

6I

F

Medium

8I

G

Large

10I

H

Large

12I

I

Large

14I

J

X-Large

16I

K

X-Large

18I

L

X-Large

20I

M

X-Large

22I

N

X-Large

J Cups

AU Size

BOOMBA Bra Size

Size Category

6J

G

Large

8J

H

Large

10J

I

Large

12J

J

X-Large

14J

K

X-Large

16J

L

X-Large

18J

M

X-Large

20J

N

X-Large

22J

O

X-Large

K Cups

AU Size

BOOMBA Bra Size

Size Category

6K

H

Large

8K

I

Large

10K

J

X-Large

12K

K

X-Large

14K

L

X-Large

16K

M

X-Large

18K

N

X-Large

20K

O

X-Large

22K

P

2X-Large

L Cups

AU Size

BOOMBA Bra Size

Size Category

6L

I

Large

8L

J

X-Large

10L

K

X-Large

12L

L

X-Large

14L

M

X-Large

16L

N

X-Large

18L

O

X-Large

20L

P

2X-Large

22L

Q

2X-Large

M Cups

AU Size

BOOMBA Bra Size

Size Category

6M

J

X-Large

8M

K

X-Large

10M

L

X-Large

12M

M

X-Large

14M

N

X-Large

16M

O

X-Large

18M

P

2X-Large

20M

Q

2X-Large

22M

R

2X-Large

N Cups

AU Size

BOOMBA Bra Size

Size Category

6N

K

X-Large

8N

L

X-Large

10N

M

X-Large

12N

N

X-Large

14N

O

X-Large

16N

P

2X-Large

18N

Q

2X-Large

20N

R

2X-Large

O Cups

AU Size

BOOMBA Bra Size

Size Category

6O

L

X-Large

8O

M

X-Large

10O

N

X-Large

12O

O

X-Large

14O

P

2X-Large

16O

Q

2X-Large

18O

R

2X-Large

P Cups

AU Size

BOOMBA Bra Size

Size Category

6P

M

X-Large

8P

N

X-Large

10P

O

X-Large

12P

P

2X-Large

14P

Q

2X-Large

16P

R

2X-Large

Q Cups

AU Size

BOOMBA Bra Size

Size Category

6Q

N

X-Large

8Q

O

X-Large

10Q

P

2X-Large

12Q

Q

2X-Large

14Q

R

2X-Large

R Cups

AU Size

BOOMBA Bra Size

Size Category

6R

O

X-Large

8R

P

2X-Large

10R

Q

2X-Large

12R

R

2X-Large

S Cups

AU Size

BOOMBA Bra Size

Size Category

6S

P

2X-Large

8S

Q

2X-Large

10S

R

2X-Large

T Cups

AU Size

BOOMBA Bra Size

Size Category

6T

Q

2X-Large

8T

R

2X-Large

U Cups

AU Size

BOOMBA Bra Size

Size Category

6U

R

2X-Large

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!