Insta Bra Fit Finder

Find your bra size now! Once you know it, make sure to check out each product’s size chart.

Your KB Bra size: -

Measuring Yourself

Did you know 8 out of 10 women are wearing the wrong bra size? We want to get you in the right bra - right away - so we recommend carefully taking your measurements and following each product’s size chart before purchasing. So, how do you measure?

Wear an unpadded and noncompressive bra that fits you well. If you're nursing, try to measure while your breasts are full. If you don’t have a flexible tape measure, use something non-stretchy like a necktie or string, and then measure that length with a tape measure or ruler.

  • #1 Underbust

    Measure directly under your breasts (snug, but not tight) while keeping the measuring tape level. Round up or down to the next even, whole number. This even number is your band size, the number part of your bra size.

  • #2 Fullest Bust

    Measure around the fullest part of your breasts while keeping the measuring tape level. This number is your bust size.

  • #3 Cup Size

    Subtract your band size from your bust size to find your cup size, the letter part of your bra size. Each inch of difference is one letter, so a 6-inch difference would be an F cup (F is the sixth letter in the alphabet).

Find the Perfect Fit

Is a Busty size right for me?

All of our bras come in Busty sizes, which are designed specifically for DD/E cups and above. Our Busty sizes have a variety of design features for superior comfort and support for larger breasts, like expanded fabric in the cups, extra-supportive chest bands, and wider straps. You may also like Busty sizes if you're more comfortable with a little extra space in your bra cups or need extra room for engorged breasts. Click here to learn more about Busty sizing.


For best fit, measure around the fullest part of your hips. If you’re pregnant, the fullest part of your hips may include some of your baby bump. Then, use the following size guide:

Hips (in) 33 - 35 36 - 38 39 - 41 42 - 44 45 - 48
*Measurements are in inches

Apparel and Pajamas

If you’re shopping for clothes to wear in your last trimester, we occasionally recommend sizing up. Make sure to check out each product’s size chart for more information. If we don’t recommend sizing up, order your normal size based on each product’s size chart.

Getting the Perfect Fit

Where to Measure

General KB Size US Size Fullest Bust (in) Waist (in) Hips (in)
XS* 0 27 - 30 24 - 26 32 - 34
S 2 - 4 31 - 34 27 - 30 35 - 37
M 6 - 8 35 - 38 31 - 33 38 - 40
L 10 - 12 39 - 42 34 - 36 41 - 43
XL 14 - 16 43 - 46 37 - 39 44 - 46
XXL* 18 - 20 47 - 50 40 - 42 47 - 49
XXXL* 22 - 24 51 - 54 43 - 45 50 - 52
*Limited styles available

If you need any help at all, message us so we can help you get the perfect fit!