Claire Bennett spent more than 10 years fitting women in specialty lingerie boutiques before building this site. Almost every calculator and guide here comes directly from fit problems she saw in real fitting rooms week after week. [ADD REAL DATA: boutique names, city or region, and exact years Claire worked in-store.]
The Problem She Kept Seeing
Most shoppers walking into a fitting room had never been measured properly. They wore whatever size they bought years earlier, or a number from a store chart that added four extra inches to their ribcage.
Usually that number was off by at least one band size and two cup letters. Bodies change with weight shifts, age, pregnancy, and nursing, and different brands cut the same tag size differently.
Why She Built This Site
Not everyone lives near a good lingerie boutique, and plenty of women prefer to measure at home in private. Claire built Bra Size Calculator so you can use the same measure-first steps she used in-store, free and without a salesperson hovering nearby.
Every calculator here starts from your actual underbust measurement and runs inside your browser without asking for an email address.
Why Calculators Help Alongside In-Store Fittings
A skilled in-store fitting is great when you get a patient fitter. Over the years, Claire saw both careful boutique fittings and rushed mall measurements that sent women home in the wrong band size anyway.
An online calculator cannot feel how stiff a band fabric is on your ribs, and we say that plainly. What it does give you is a steady, repeatable starting size every time you measure.
No Fake Credentials, on Purpose
Claire is not a doctor or physical therapist, and bra fitting does not have a single government license or universal certification board. She will not invent a fancy certificate title to sound more official.
Her background is a decade of hands-on boutique fitting and checking brand size charts against real measurements. If a chest or shoulder issue sounds medical, such as sharp pain or a sudden lump or size change on one side, skip the calculator and talk to a doctor.
How the Site Is Run Today
Claire writes and updates the fitting guides here alongside a small chart-checking desk that tracks brand sizing across US, UK, EU, French, Australian, and Japanese labels. Every calculator shows its math so you can see why you got your result.