The Rundown on onewith swim Sizing

Since we launched our newest collection of onewith swimsuits that fit like underwear, a common question we’ve gotten asked is to show what our three new tops look like on a model with a larger cup size and smaller band size. We covered that with a reel going in-depth about the tops’ sizing on our IG feed (check it out here), and we wanted to take the opportunity to expand on our better-than-seamless swimwear sizing and why it's so vital for achieving our signature lay-flat, dig-free swimwear look. 

We do not size by cup; we recommend you buy the same size onewith swim bikini top as you would a tight camisole or bralette. Sizing is subjective and our bodies are more dynamic than numbers on a size chart could ever allow for, this is the most blanket guidance we can give. One of the most common reasons for exchanges is people thinking they need to size up in a bikini top due to their cup size, and end up needing to size down back to what they would normally order. You want your suit to be snug and second-skin-like, not only to get the onewith fit but also because a suit that is too big will become, naturally, less secure when in the water. We’ve made it so simple in this way, we DO NOT size by cup! 

A friendly reminder that not all models we share on our feeds are comfortable disclosing their measurements, cup size, band size, etc., and we also feel that making sizing calls based on images is not the most accurate way to size yourself. Please reference our size guide and our fit notes on each item as each body is different, and what onewith swim was created to support! Check out more helpful tips and shop our women's flattering swimwear at onewithswim.com and on our Pinterest + Instagram feeds. See you there!