Bra Size Conversion Chart
Use the band table as the stable part of the conversion and verify the brand’s cup progression separately.
Illustrative band-label comparison — not the US/UK fitting calculator
The centimeter underbust intervals below follow a Wacoal Singapore/Japanese-style reference, paired with illustrative US/UK and EU band labels. They are not the US Knix or UK Brastop underbust formulas used by our calculator. Do not use this cross-reference to derive a cup size or assume identical fit across brands. Source: Wacoal Singapore guide.
| Underbust | US | UK | EU |
|---|---|---|---|
| 68–72 cm | 32 | 32 | 70 |
| 73–77 cm | 34 | 34 | 75 |
| 78–82 cm | 36 | 36 | 80 |
| 83–87 cm | 38 | 38 | 85 |
| 88–92 cm | 40 | 40 | 90 |
| 93–97 cm | 42 | 42 | 95 |
Band-label methods differ across makers. These are printed band references, not the actual underbust-to-band mapping of Knix or Brastop. For a starting physical measurement use the source-specific calculator.
Illustrative cup-letter sequence (not a fitting formula)
| Example inch step (not paired with band table) | US | UK |
|---|---|---|
| 1 in / 2.5 cm | A | A |
| 2 in / 5 cm | B | B |
| 3 in / 7.5 cm | C | C |
| 4 in / 10 cm | D | D |
| 5 in / 12.5 cm | DD/E | DD |
| 6 in / 15 cm | DDD/F | E |
The cup rows are illustrative US/UK naming examples, not a verified measurement-to-size chart for either Knix or Brastop. Larger cup letters, labels like DD/E and complete US ↔ UK bra sizes are brand/system dependent. Never combine these rows with the centimeter band comparison to compute a fitted size.
Separate band conversion from cup conversion
The shared underbust-centimeter rows are illustrative Wacoal-style band-label pairs, not a universal method for calculating a Knix US or Brastop UK band. Check the published source-specific chart.
A chart that shows only band numbers cannot safely answer a full US-to-UK-or-EU bra conversion on its own.
Why complete-size comparison matters
Cup volume depends on band size, and letter sequences are not globally synchronized. Compare 34C as a complete size rather than treating “34” and “C” as independent universal values.
When a brand publishes its own conversion chart, use that chart as the final reference.
How this guidance is checked
These sources support the measurement method and help check real-world variation. They are not presented as one universal brand-size table.
- Bra Fit Calculator — Wacoal. Bra measurement cross-check using underbust and fullest-bust measurements and brand-specific fitting logic.
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