Bra Size Calculator: United Kingdom
Measure once, and this calculator highlights your size in United Kingdom's UK convention while showing all 7 international systems for imported brands. Enter your snug underbust and fullest bust below.
This calculation runs entirely in your browser. Your measurements are never stored or sent anywhere.
Shopping for bras in United Kingdom
The UK has the deepest cup ladder in the world, running D, DD, E, F, FF, G, GG and beyond, because British full-bust brands built their ranges around real fittings rather than compressing everyone into DDD. If you measure beyond a D, UK sizing describes you more precisely than US labels can.
Bravissimo, Freya and Fantasie cut for projected shapes with firm bands. Expect a new band to feel snugger than mall brands; that firmness is the support working.
Brands you will commonly see: M&S, Bravissimo, Freya, Fantasie, Boux Avenue.
Frequently asked questions
Last updated August 2026.