Knix Bra Size Chart & Sizing
Wireless-first: bonded, seamless bras sold in the brand's own numeric size grid, plus a small underwire range.
Knix in numbers
Knix made its name with leakproof underwear and wireless bras. Its wireless styles use a numbered-alpha grid (sizes 1–8 with plus extensions) that maps to bra sizes on a chart; support relies on band width and fabric compression, so the map matters.
Your measured size in Knix
How this is computed: your US size read straight onto the US label, then adjusted for how Knix typically grades: true bands, true cups. This brand sells many styles in alpha sizes (S/M/L or numeric athletic sizes) that fit the ribcage rather than the cup: the conversion below applies to its numbered bra-sized styles; for alpha styles use the brand grid and expect support to fall off above a C or D.
Where Knix sits on the size grid
Cups Wireless sizes span roughly 30A–44DD in the brand's grid. Not every band–cup combination exists; the largest cups usually appear on mid-range bands only.
Best for:
- Wireless everyday support
- Seamless under knits
- Sport (Catalyst) in wireless
Knix bra size chart (US sizing)
Open the interactive size chart →
Knix labels in United States notation. Rows are bands (US number, US equivalent in brackets); columns are cup letters as Knix writes them. Each cell links to that size's guide.
| Band | A | B | C | D | DD | DDD |
|---|
Coverage is approximate to the brand's core collections; the largest cups typically exist on mid-range bands only. US DDD is written DDD here.
Does Knix run small or big?
Knix bands run true to size: start with your measured band on the loosest hook, and expect it to feel snug for the first week if you are coming from an add-inches size.
Knix cups grade true to the measured difference: a gap or overflow in the measured letter is a shape signal, so change the cut before the size.
Knix wires are average width for the US system. Straps: Standard.
What to try at Knix
| Line | Notes |
|---|---|
| Wingwoman | contour wireless, the flagship |
| Padded V-Neck | wireless plunge |
| Longevity | underwire in numbered sizes |
| Catalyst | sports bra |
| Shape | Try |
|---|---|
| Full on bottom | Padded V-Neck |
| Full on top | Wingwoman full coverage |
| Shallow | Wingwoman |
| Projected | Longevity |
| Wide-set | Padded V-Neck |
Not sure of your shape? The fit guide explains the five shapes and how to recognize yours.
Knix vs other brands
Side-by-side sizing, fit and your size in both. All comparisons →
Similar brands, different fit
Alpha-sized shapewear-adjacent bras and bralettes, plus a numbered underwire range: the sizing story is knowing which you're buying.
Basics-first DTC: a small line of everyday bras (lined, wireless and bralette) across a broad band and cup grid.
One of the oldest names in the category, now a comfort and wireless mainstream brand.
Knix sizing: answered
How does Knix bra sizing work?
Wireless styles use Knix's own numeric grid that maps several bra sizes onto each number: use the chart; the Longevity underwire line uses standard bra sizes. Bands run true; compression styles feel snug by design.
What sizing system does Knix use?
Knix sizes in United States (US) convention: bands Alpha (1–8 numbered-alpha) on wireless; numbered on select underwire, cups Wireless sizes span roughly 30A–44DD in the brand's grid. US labels: a US 34C is a 34C here.
Does Knix run big or small?
Knix bands run true to size: start with your measured band on the loosest hook. Knix cups grade true to the measured difference.
What is my size in Knix?
Start with your measured size, convert it to US notation, then apply the brand's grading: start with your measured band on the loosest hook. The calculator on this page does both.
What is Knix best known for?
Wingwoman: contour wireless, the flagship. Also: Padded V-Neck (wireless plunge); Longevity (underwire in numbered sizes).
Which Knix bra suits my shape?
Full on bottom: Padded V-Neck; Full on top: Wingwoman full coverage; Shallow: Wingwoman; Projected: Longevity; Wide-set: Padded V-Neck.
Are Knix sizes the same as Skims?
Same notation where the systems match, different fit. Knix: true band, true cup, average wire. Skims: true band, true cup, average wire. Convert the label, then apply the fit notes.
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