Cup Size Comparison
Visual comparison of UK bra cup sizes from AA to K.
Side-profile comparison of UK cup sizes AA through F. Each silhouette represents the same body with only the cup projection changing.
Select a Cup Size
Tap any cup size to see its measurement, EU equivalent and fitting notes.
UK Cup Size Measurement Table
Cup size is calculated from the difference between your full bust and your underbust measurement. UK cups differ from EU cups — this table shows both.
| UK Cup | EU Cup | Difference (cm) | Difference (inches) |
|---|---|---|---|
| AA | AA | Less than 2.5 cm | Less than 1 inch |
| A | A | 2.5 cm | 1 inch |
| B | B | 5 cm | 2 inches |
| C | C | 7.5 cm | 3 inches |
| D | D | 10 cm | 4 inches |
| DD | E | 12.5 cm | 5 inches |
| E | F | 15 cm | 6 inches |
| F | G | 17.5 cm | 7 inches |
| FF | H | 20 cm | 8 inches |
| G | I | 22.5 cm | 9 inches |
| GG | J | 25 cm | 10 inches |
| H | K | 27.5 cm | 11 inches |
| HH | L | 30 cm | 12 inches |
| J | M | 32.5 cm | 13 inches |
| JJ | N | 35 cm | 14 inches |
| K | O | 37.5 cm | 15 inches |
Important:UK cup letters and EU cup letters are not the same above a D cup. UK DD = EU E, UK E = EU F, UK F = EU G, and so on. When shopping from a European brand, always check the brand's own size guide.
Our calculator shows both your UK size and EU equivalent.
Expert Cup Sizing Verification
Every cup scale comparison and volume analysis is vetted by certified lingerie experts.
Eleanor Vance
Certified Bra Fitter & Lingerie Consultant
Over 12 years of professional fitting experience at leading UK lingerie retailers, including Bravissimo and Marks & Spencer. Specially certified in maternity, teen first-fit, and post-surgery supportive consultations.
Sizing Math & Rounding Logic
Our calculator implements the industry-standard **modern fitting method** rather than the obsolete "plus-4" retail formula. Band sizes are derived directly from snug ribcage measurements in inches (rounded to the nearest even number). Cup sizes are calculated using the precise 1-inch difference increments between fuller bust and underbust measurements (e.g. 4" = D, 5" = DD, 6" = E).
Sourced Claims & Studies
Medical and biomechanical research shows that up to **80% of UK women wear the wrong bra size**. According to breast health clinical research from the **University of Portsmouth (Department of Sport and Exercise Science)**, properly fitted encapsulation support reduces vertical breast movement by up to 59%, significantly preventing exercise-induced breast discomfort and cooper's ligament stretching.