Acerca de Bra size calculator
Band size comes from the snug measurement around the ribcage under the bust, and cup size from how much the bust measurement exceeds the band. The default plus-zero method, used in Triumph's UK fitting guide, rounds the underbust to the nearest even inch and counts one cup per inch of difference: 0 is AA, 1 A, 2 B, 3 C, 4 D and 5 DD. The traditional plus-four method and the European standard EN 13402, which works in centimeters, are the other two options.
An underbust of 31.5 inches and a bust of 37 inches give a 32 band and a 5-inch difference, a US and UK 32DD. The same size is a 70E in European sizes, 85E in French and Belgian sizes and 10DD in Australia, from the Fantasie and Freya conversion charts.
Brands size differently and the methods disagree by one or two band sizes, so treat the result as a starting point for a fitting. The sister sizes hold the same cup volume on a band one size up or down.
Preguntas
How do I measure my bra size?
Measure snugly around the ribcage directly under the bust for the band, and around the fullest part of the bust for the cup, with the tape level. Triumph's UK guide rounds the underbust to the nearest even inch, then subtracts that band from the bust: each inch is one cup. A 33.5-inch underbust and 37-inch bust give a 34 band and a 3-inch difference, a 34C.
What are sister sizes?
Sister sizes share the same cup volume on a different band: go up one band size and down one cup, or down one band and up one cup. Wacoal's b.tempt'd fit guide gives 32C and 36A as the sister sizes of a 34B. They help when a band feels too tight or loose but the cups fit, or when a style doesn't come in your usual size.
Should I add 4 inches to my band measurement?
The plus-four rule adds 4 inches to an even underbust and 5 to an odd one, so a 30-inch ribcage wears a 34 band. Wikipedia's Bra size article records Kohl's using it in 2013. Triumph's UK guide instead rounds the measured underbust to the nearest even inch, which for a 30-inch ribcage and 36-inch bust gives a 30E instead of the plus-four 34B.
How do US, UK and European bra sizes convert?
Bands follow a fixed pattern: UK and US 32 is 70 in Europe, 85 in France and Belgium and 10 in Australia, and each band step adds 5 cm. Cups match up to D; after that the UK uses DD, E, F, FF, the US DD, DDD, G, H, and Europe E, F, G, H, one letter per step, according to the Fantasie and Freya charts. A UK 34E is a US 34DDD and an EU 75F.
How does the European standard EN 13402 size bras?
EN 13402 labels a bra with the underbust in centimeters, rounded to the nearest 5, and a cup letter from the difference between bust and underbust in 2 cm steps: AA is 10–12 cm, A 12–14, B 14–16, C 16–18 and D 18–20. An 89 cm underbust and 108 cm bust have a 19 cm difference, so the standard's size is 90D, which converts to a UK 40D.
¿Qué precisión tiene «Bra size calculator»?
La precisión depende de tus datos y de los supuestos del método. El cálculo decimal usa 50 cifras significativas, pero las estimaciones, los métodos numéricos y los datos de origen pueden ser menos precisos; el redondeo mostrado no elimina esos límites. Ejemplos resueltos comprobados con fuentes independientes: 6. Por ejemplo, «31.5 in underbust, 37 in bust (plus zero)» se comprueba con Triumph UK method: 31.5 → 32 band, 37 − 32 = 5 in = DD; conversions from the Fantasie chart (UK DD = EU/FR E = AU DD = US DD; 32 = EU 70 = FR 85 = AU 10).
¿De dónde procede el método?
Triumph UK — Bra size calculator and fitting guide (round the underbust to the nearest even inch; 1 inch per cup); EN 13402-3 bra labelling (underbust to the nearest 5 cm; AA = 10–12 cm … H = 26–28 cm), summarised with the 90D worked example; Fantasie — International size guide (UK, EU, FR, AU/NZ, US band and cup conversion); Wacoal America — Size charts (US and UK cup sequences); b.tempt'd by Wacoal — Fit calculator and sister sizes.