How to Measure Bra Size at Home: Step-by-Step Guide

To measure bra size at home, you need a soft tape measure and two numbers: measure snugly around your ribcage just under the bust for the band, then loosely around the fullest part of the bust. Round the band to a whole number, then subtract it from the bust measurement. Each inch of difference equals one cup size.

A measured size is a starting point, not a final verdict. Styles fit differently, so the fit checks below matter just as much as the tape.

How do you measure your band and bust step by step?

Stand in front of a mirror so you can see that the tape stays level all the way around. Wear an unpadded bra that fits fairly well, or no bra.

1. Measure your band. Wrap the tape around your ribcage directly under your bust, where a band would sit. Keep it snug and level, and breathe out normally before you read it.
2. Round the band. Round to the nearest whole inch. Bands come in even sizes, so if you get an odd number like 33, start with 34.
3. Measure your bust. Wrap the tape loosely around the fullest part of your bust, usually across the nipples. It should rest on the skin without pressing in.
4. Try the lean-forward check. Bend forward at the waist and measure the fullest part again. If this number is larger, average the two readings for a truer cup.
5. Do the math. Subtract your band size from your bust measurement. The difference in inches gives your cup letter.

For example, an underbust of 33 rounds to a 34 band. A bust of 38 minus 34 is 4, which is a D cup, so the starting size is 34D.

How do you calculate your cup size?

Use the difference between your bust measurement and your band size. These are standard U.S. cup letters.

Some bras group two cups into one option, such as D/E or E/F, because the cup fabric stretches to fit a range. If your size lands on either letter, that combined option is the one to try.

The Underwire Push-Up Bra is sold by band and cup, from a 34 to a 48 band with grouped cups from B/C to G. It has alloy underwires, three-quarter cups, wide side wings, side boning and a three-row hook closure.

What are sister sizes and when should you use them?

Sister sizes hold the same cup volume on a different band length. When you go down one band size, go up one cup letter, and when you go up one band size, go down one cup letter.

Use a sister size when the cups fit but the band feels too loose or too tight. It is also handy when your exact size is not offered in a style you love.

How can you tell if a bra fits correctly?

Fasten a new bra on the loosest hook so you can tighten it as the band relaxes over time. Then lean forward and scoop the breast tissue from the sides into each cup before you check these four points.

• Band: it sits level all the way around and does most of the supporting. You should fit about two fingers under the back, but no more. If it rides up, try a smaller band.
• Straps: they stay put without digging in or leaving deep marks. If you have to tighten them a lot to feel supported, the band is likely too big.
• Center gore: on an underwire bra, the center panel between the cups should lie flat against your chest. If it floats away, try a larger cup.
• Cups: the fabric is smooth, with no spilling over the top or sides and no wrinkles or gaps. Wires should sit around the breast tissue, not on it.

When does wireless or underwire fit better?

Wireless bras are more forgiving. Many use S to XL style sizing and stretchy seamless fabric, so they adapt if you sit between sizes or your shape shifts during the month.

Underwire bras depend on an exact band and cup match because the wire has to circle the breast tissue. When the size is right, they give defined shape and separation under fitted clothes. For a deeper look at comfort and support, read wireless vs underwire bras.

The Full Coverage Smoothing Wireless Bra uses letter sizes from S to 2XL. It has no underwire or padding, a wide bottom band, wide adjustable straps and a four-row hook-and-eye closure with an extension hook.

For fuller cups that want an underwire without bulk, the Sheer Mesh Full Coverage Unpadded Underwire Bra comes in bands 34 to 42 and cups B to DDD. It has side boning, adjustable straps and a sheer mesh upper cup.

Browse every style in our bras collection, and if you are planning a fitted outfit, our guide on how to choose shapewear covers the layer underneath. Shipping and return details are in our FAQ.

FAQ

Should I measure my bra size with or without a bra on?

Wear a lightly lined or unpadded bra that fits reasonably well, or no bra at all. Padding and push-up cups add volume and can make the bust measurement read larger than you are.

Why is my measured size different from the size I wear?

Bodies change, bra styles vary and some older methods add inches to the band. Use your measured size as a starting point, then adjust with sister sizes and the fit checks until the bra feels right.

How often should I measure my bra size?

Measuring once or twice a year is a good habit. It is also worth checking after any noticeable change in your body, or when bras that used to fit start to ride up, dig in or gap.

What if my band size is an odd number?

Bras are usually sold in even band sizes. Try the next even size up first, then the size below if the band feels loose, and adjust the cup with sister sizing so the volume stays the same.

What if I am between sizes?

A wireless bra in letter sizing is often more forgiving between sizes because the fabric stretches. For underwire bras, try your sister size and focus on how the band and wire sit.

Can I return a bra that does not fit?

Bras that are unworn and unwashed, with tags and original packaging, can be returned within 30 days of delivery. Email support@audreysboutiqueshop.com with your order number to start.