Why we built this
Bra sizing is unnecessarily confusing. A woman can be a 34C in one brand, a 34D in another, and a 75C in a European store — all at the same time. When she shops online from Shein, ASOS, or a French lingerie brand, she's essentially guessing.
Studies suggest up to 80% of women wear the wrong bra size — not because they don't care, but because the information to get it right is scattered, contradictory, and buried in unhelpful size charts.
FindMyBraSize was built to fix that. One clean tool. No sign-up. No ads blocking the result. Just the answer.
What we do
FindMyBraSize offers two tools in one. The calculator takes your underbust and bust measurements and tells you your size across every major international system. The converter takes a size you already know and translates it into US, UK, EU, AU, IT and JP sizing instantly.
We also explain what each measurement means, how to take it properly, what sister sizing is, and how to use it when a bra almost — but doesn't quite — fit. The goal is that any woman, regardless of how much she knows about bra sizing, leaves with a clear answer.
Our values
Always free
The tool will never be paywalled. Every woman deserves to know her size without paying for it.
Global by default
We support US, UK, EU, AU, IT and JP sizing because women shop globally and deserve global answers.
Accuracy first
Our conversion tables are based on industry standards, not guesswork. We update them when standards change.
All body types
Our calculator works for every band and cup size — from AA to K, from 28 to 48 band. No one is excluded.
Ready to find your perfect fit?
Takes less than 60 seconds. No sign-up required.
Calculate My Size →