How To Measure Bra Size - Bra Sizing Calculator

How to Measure Bra Size - Bra Sizing Calculator

Wondering about sports bra sizing and how to measure bra size options? Our bra size calculator makes crunching the numbers easy when you need to know how to fit a bra. Just use our bra size calculator or bra size chart below to see how to measure your bra size.

bra fit calculator

All it takes is three quick measurements! Need more detailed directions? Everything is explained below.

How To Measure

We've done our best to take out the guesswork and make finding your cup size and band size simple. Push-up bras and padding can skew things, so pull on a shelf bra camisole or your best fitting everyday bra and grab an inch tape measure.

Step 1: Measure around your chest, just under the arms and above the bust. Make sure that the tape measure is taut and is straight across your back, but not tight, or that could result in a squeeze later. Breathe out, relax your shoulders. We'll get through this together. If the measurement is an odd number or a half size, round it up to the next even number inch (for example, 33.5 will actually be 34). This number is known as your band size. Unsure you've got it right? Take a seat - our chests expand some when seated.

Step 2: Now it's time to measure your cup size. Take your bust measurement around the fullest point of your breast. This could be at the nipple, but everyone's breast shapes are different. This will be one of two measurements that you need to determine your cup size.

Step 3: For the final measurement, measure just under the breast around your ribcage.

Got the measurements? Good. It's time to calculate your bra size.

What you should know
  • Women can experience upwards of nine major bra size changes in their lives, so it's a good idea to get sized at least once a year.
  • Whether you're shopping for an everyday bra or a sports bra, the size you wear is the same in both. No need to size down for more support!
  • Bras do eventually get worse for the wear due to all that washing. It's important for your girls that no sports bra ever celebrate a birthday!

Buying a sports bra and not sure where to begin? Our Sports Bra FAQ can help.


Prefer using a chart instead of a bra size calculator? Using the same measuring guidelines above, reference the chart below to find your cup size and band size.

What’s my band size?
Measure above the bust, around your chest, just under the arms (Step 1 above).

Above Bust Measurement Band Size
29in - 31in 30
31in - 33in 32
33in - 35in 34
35in - 37in 36
37in - 39in 38
39in - 41in 40
41in - 43in 42
43in - 45in 44

What’s my cup size?

First, measure around the fullest part of your bust (Step 2 above).

Next, measure around your rib cage, just beneath your breasts (Step 3 above). Deduct your rib cage measurement from your bust measurement in order to determine your recommended cup size (round up if between sizes.) Use the chart below to figure out your cup size!

If Bust Measurement Minus
Rib Cage Measurement Equals:
Then Cup Size Is:
1 inch AA
2 inches A
3 inches B
4 inches C
5 inches D
6 inches DD
7 inches E (DDD)
8 inches F (DDDD)

Bra Size Calculator & Bra Size Chart

Wondering what bra size you are? Title Nine's bra size calculator has you covered. T9 will help you learn about sports bra sizing and how to measure for the right comfort and fit. From AA to DDD Title Nine's bra size calculator will help you find the right bra that will have you feeling strong and confident throughout the day. Check out T9's bra fitting guide to help find the right fitting sports bra to keep you in the game.