
Learning how to measure bra size can feel uncomfortable, but knowing your measurements — and keeping them written in a note on your phone or somewhere else that is accessible when the bra-shopping mood strikes — will make bra-shopping so much easier, especially for online shoppers. All you need for measuring your bra size is a measuring tape and a little free time; and you will have saved yourself a lot of bra-shopping misery.
Find Your Band Size

Take a measuring tape and wrap it around your rib cage directly under your bust, where a bra band would sit.
If you get an odd number, round it to the next even number.
[You don’t need to add four inches if the band size is even, or five inches if it’s odd. This was designed as a method for measuring way back in the 1950s when bras were made from silk and satin and didn’t stretch. The 4 inches extra allowed breathing room, something which in 2021 is completely redundant as all bras now have elastic and stretch in them]
Take Your Bust Measurement

Move the measuring tape to the fullest part of your busts, around nipple level.
Ensure it is secure and snug, but not too tight
Related: How To Wear A Bra Properly
Find Your Cup Size

Take your Bust measurement (usually the bigger number), and subtract your Band measurement. This number corresponds with your Breast Size.
For example, 36 inches (bust) – 34 inches (band) = 2 inches. This points to a B cup size (because of the 2-inch difference).
The Bra Size Chart

Your bra size is your band size with your cup size. Hence, the example above represents a 34B bra size. That is 34-inch band size and B cup size.
If you need to go down a cup size for fit, go up one band size, and vice versa. For example, if 34C is too big for you in the cups, move to 36B. Use the Bra Size Chart here to make sure you are moving up or down a bra size correctly, and remember that your bra size might change slightly, depending on the brand or type of bras. It may take some trial and error to find the perfect fit.