All you need is a soft measuring tape. 

1. Measure your underbust
   Wrap the tape measure snugly around your body, right underneath your bust. Keep the tape level and comfortable snug, not too tight. 
   
   
2. Check your measurement
   Your underbust measurement in inches or centimeters will help you find your onion bra size. 
   
   For example, if your underbust measures 29 inches, you're a medium in our size guide. That's it. No complicated cup-size calculations. No guessing your band size. 
   
   
3. Between sizes? Size up.
   If your measurement falls between two onion sizes, we recommend sizing up for a more comfortable fit. 

Why doesn't onion use traditional bra sizes? 

Because bra sizing shouldn't be this complicated. 

Your size can vary between different bra brands, and a 34B in one brand doesn't always fit like a 34B in another. Instead of making you figure out your band and cup size, we created a simple sizing system based on your underbust measurement. 

Whether you're looking for a comfortable everyday bra, wireless bra, supportive bra, or a bra without underwire, we want finding your size to be easy. 

What about your cup size? 

Don't worry about your cup size. We've got you. Unlike traditional bras, onion cups are designed to be stretchy and adaptable to your body, so you don't need to perfectly match a traditional A, B, C, D, or DD cup size. 

For example, an onion XL can comfortable accommodate anywhere from an A cup to a DD, depending on your band/underbust measurement and how you prefer your bra to fit. 

Your body isn't one-size-fits-all, and your bra shouldn't be either. Focus on your underbust measurement and let the fabric do the rest. 

Will my bra stretch over time? 

Your onion bra will relax a little with wear, which is completely normal. It should return to its normal shape after washing. 

In fact, a bra is more likely to stretch when it's too tight and being stretched throughout the day. That's why finding the right size is important. You should experience minimal stretching when your bra fits properly. 

If you're concerned about stretching, we recommend starting on the loosest hook when you first get your bra. As the band naturally relaxes over time, you can move to the tighter hooks to extend the life of your bra. 

Still not sure what size you need? DM us. A real human will help you figure it out 💌