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

November 15, 2024

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

DD

6

E

7

F

8

FF

9

G

10

GG

11

H

12

HH

13

J

14

JJ

15

K

16

KK

17

L

18

LL

19

M

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

UK Size

BOOMBA Bra Size

Size Category

28A

AA

X-Small

30A

AA

X-Small

32A

AA

X-Small

34A

A

X-Small

36A

B

Small

38A

C

Small

40A

D

Medium

42A

E

Medium

44A

F

Medium

B Cups

UK Size

BOOMBA Bra Size

Size Category

28B

AA

X-Small

30B

AA

X-Small

32B

A

X-Small

34B

B

Small

36B

C

Small

38B

D

Medium

40B

E

Medium

42B

F

Medium

44B

G

Large

C Cups

UK Size

BOOMBA Bra Size

Size Category

28C

AA

X-Small

30C

A

X-Small

32C

B

Small

34C

C

Small

36C

D

Medium

38C

E

Medium

40C

F

Medium

42C

G

Large

44C

H

Large

D Cups

UK Size

BOOMBA Bra Size

Size Category

28D

A

X-Small

30D

B

Small

32D

C

Small

34D

D

Medium

36D

E

Medium

38D

F

Medium

40D

G

Large

42D

H

Large

44D

I

Large

DD Cups

UK Size

BOOMBA Bra Size

Size Category

28DD

B

Small

30DD

C

Small

32DD

D

Medium

34DD

E

Medium

36DD

F

Medium

38DD

G

Large

40DD

H

Large

42DD

I

Large

44DD

J

X-Large

E Cups

UK Size

BOOMBA Bra Size

Size Category

28E

C

Small

30E

D

Medium

32E

E

Medium

34E

F

Medium

36E

G

Large

38E

H

Large

40E

I

Large

42E

J

X-Large

44E

K

X-Large

F Cups

UK Size

BOOMBA Bra Size

Size Category

28F

D

Medium

30F

E

Medium

32F

F

Medium

34F

G

Large

36F

H

Large

38F

I

Large

40F

J

X-Large

42F

K

X-Large

44F

L

X-Large

FF Cups

UK Size

BOOMBA Bra Size

Size Category

28FF

E

Medium

30FF

F

Medium

32FF

G

Large

34FF

H

Large

36FF

I

Large

38FF

J

X-Large

40FF

K

X-Large

42FF

L

X-Large

44FF

M

X-Large

G Cups

UK Size

BOOMBA Bra Size

Size Category

28G

F

Medium

30G

G

Large

32G

H

Large

34G

I

Large

36G

J

X-Large

38G

K

X-Large

40G

L

X-Large

42G

M

X-Large

44G

N

X-Large

GG Cups

UK Size

BOOMBA Bra Size

Size Category

28GG

G

Large

30GG

H

Large

32GG

I

Large

34GG

J

X-Large

36GG

K

X-Large

38GG

L

X-Large

40GG

M

X-Large

42GG

N

X-Large

44GG

O

X-Large

H Cups

UK Size

BOOMBA Bra Size

Size Category

28H

H

Large

30H

I

Large

32H

J

X-Large

34H

K

X-Large

36H

L

X-Large

38H

M

X-Large

40H

N

X-Large

42H

O

X-Large

44H

P

2X-Large

HH Cups

UK Size

BOOMBA Bra Size

Size Category

28HH

I

Large

30HH

J

X-Large

32HH

K

X-Large

34HH

L

X-Large

36HH

M

X-Large

38HH

N

X-Large

40HH

O

X-Large

42HH

P

2X-Large

44HH

Q

2X-Large

J Cups

UK Size

BOOMBA Bra Size

Size Category

28J

J

X-Large

30J

K

X-Large

32J

L

X-Large

34J

M

X-Large

36J

N

X-Large

38J

O

X-Large

40J

P

2X-Large

42J

Q

2X-Large

44J

R

2X-Large

JJ Cups

UK Size

BOOMBA Bra Size

Size Category

28JJ

K

X-Large

30JJ

L

X-Large

32JJ

M

X-Large

34JJ

N

X-Large

36JJ

O

X-Large

38JJ

P

2X-Large

40JJ

Q

2X-Large

42JJ

R

2X-Large

K Cups

UK Size

BOOMBA Bra Size

Size Category

28K

L

X-Large

30K

M

X-Large

32K

N

X-Large

34K

O

X-Large

36K

P

2X-Large

38K

Q

2X-Large

40K

R

2X-Large

KK Cups

UK Size

BOOMBA Bra Size

Size Category

28KK

M

X-Large

30KK

N

X-Large

32KK

O

X-Large

34KK

P

2X-Large

36KK

Q

2X-Large

38KK

R

2X-Large

L Cups

UK Size

BOOMBA Bra Size

Size Category

28L

N

X-Large

30L

O

X-Large

32L

P

2X-Large

34L

Q

2X-Large

36L

R

2X-Large

LL Cups

UK Size

BOOMBA Bra Size

Size Category

28LL

O

X-Large

30LL

P

2X-Large

32LL

Q

2X-Large

34LL

R

2X-Large

M Cups

UK Size

BOOMBA Bra Size

Size Category

28M

P

2X-Large

30M

Q

2X-Large

32M

R

2X-Large

MM Cups

UK Size

BOOMBA Bra Size

Size Category

28MM

Q

2X-Large

30MM

R

2X-Large

N Cups

UK Size

BOOMBA Bra Size

Size Category

28N

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!