Cup size and band size when the underwire is gone
Short answer: Your cup size comes from the difference between your bust measurement and your underbust measurement, and that holds without an underwire too. Without a wire the fabric simply gives a little more, so there is some room in the size. Here is how to measure and choose.
What band size and cup size actually mean
The band size is the measurement around your body just under the bust, while the cup describes how much room there is for the bust itself. The two belong together, and both must fit before a bra sits properly. Without a wire there is no fixed frame, so the fabric and the band do more of the work.
How to measure the band under the bust
Take a soft tape measure and lay it level around your body, just under the bust. The tape should be snug without cutting in, and you should be able to breathe calmly. Measure twice to be sure, and use that number as your starting point when you compare with the size chart for bamboo bra without underwire.
How to measure over the bust
Then measure around the fullest part of the bust, with the tape level across your back. Do not press the bust flat while you do it. The difference between this measurement and the band measurement shows which cup suits you, and the size chart on the product page explains how to read that difference.
Cup size without an underwire has a little more give
A bra without underwire does not shape the bust with a fixed frame, so it adapts to you a little more. That means the cup size can feel more forgiving, especially in a soft and stretchy fabric. If you fall between two cup sizes, try the smaller one for more support and the larger one for more room.
Check the band before you judge the cup
The band carries most of the support, so it should sit level and snug all the way around. If you can lift it far away from your body, it is probably too big, and the cups end up doing too much. If it is too tight it can leave red marks, and then going up a size is better.
What a good cup looks like
The bust should fill the cup without spilling over the edge, and there should be no big wrinkles or empty gaps in the fabric. The cup lies softly against the skin without pressing. If you can slide one finger under the straps without them cutting in, they usually sit at a suitable tightness.
When your size changes over time
Your body changes over the years, and so do the measurements that suit you. Measure again from time to time, especially if your bra suddenly sits differently. Remember too that sizes can vary a little between cuts and fabrics, so always use the chart on the individual product page.
Combine the bra with the rest of the wardrobe
The right size also makes the rest of your clothes more comfortable. Under tops and T-shirts the cup should not show an edge or cut in at the side, and the band should lie smooth. Have a look at bamboo underwear for women and bamboo tops for women to find pieces that work together day to day.
Frequently asked questions
Should I choose a bigger cup without an underwire?
Not necessarily. You measure the same way as for a bra with underwire, but the fabric gives a little more. If you are between two sizes, try both and feel the difference.
How often should I measure myself?
Measure when you buy a new bra or when your old one suddenly sits differently. Your body changes over time, so a fresh measurement about every six months can be a good habit.
How do I know the band is too big?
If the band rides up your back or can be lifted far away from your body, it is probably too big. Try a smaller band and check that the cup still fits.
