If a listing says 75A, start from US 34A and then read the brand's cup chart.
If you often sit between A and B, compare the cup depth or consider 75B.
Cup depth can vary by brand and style.
Sports bras and wire-free bras may fit more flexibly than wired bras.
This page answers one specific size search intent. For the best fit, start with the linked main converter and use the centimeter measurements on the Chinese chart whenever they are available.
Marketplace labels are useful shortcuts, but brand charts, garment type, fabric stretch and body measurements can change the final fit. Treat the lookup as a nearest match, not a guaranteed size.
Chinese size labels are practical lookup shortcuts, not universal brand guarantees. A CN shoe label, clothing size, bra code or Taobao chart row can vary by seller, product category, last shape, fabric stretch and whether the chart shows body measurements or garment measurements.
When possible, use the centimeter value first: foot length for shoes, bust/waist/hip for clothing, under-bust and cup difference for bras, and the specific Taobao chart row for marketplace listings. Then use the converter result as the nearest US, UK or EU match.
For the broader explanation, read Chinese bra size chart to US complete guide. For why these pages give estimates instead of promises, read Why Chinese size conversion is an estimate.