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Fit notes No. 24
What is a sister size in bras?
A sister size keeps the cup volume similar while changing the band. It is a starting point, not a guarantee.
Measure first, then choose the shape. Between sizes, take the larger.
Match the piece to the outfit, the light and how long you will wear it.
Plain packaging, tracked delivery and 14-day returns with the seal intact.
A sister size is the same cup volume on a different band. For example, a 34C is often compared with a 32D or 36B, depending on the brand. Lace Index lists the actual sizes held on each product page; use the size guide as the starting point.
01
Start with the shape
If the band is too tight but the cup fits, go up a band and down a cup. If the band is too loose but the cup fits, go down a band and up a cup. The straps and cup shape can still change the fit.
02
Fit and feel
Sister sizing is not universal across brands or styles. Check the product page and the cup construction. If you are between sizes, choose the band that stays level and adjust the cup.
03
Before you order
Try the bra with the band level and the cups flat. If the centre front floats or the cup spills, the sister size is not right. Ask us with your measurements if you are unsure.
At a glance
| Category | Bras & Sets |
|---|---|
| Price | From $9.90 USD |
| Sizes | Selected styles XS–4XL; the product page lists the exact sizes held |
| Colours | Up to 12 colourways per style |
| Dispatch | Within 24 hours on business days |
| Delivery | 7–12 working days, tracked |
| Packaging | Plain, unbranded mailer |
| Returns | 14 days, hygiene seal intact |
In stock now
Pieces to start with.
| Piece | Price | Sizes | Colours |
|---|---|---|---|
| Lace-Trim Cami, Shorts and Pants Pajama Set | $9.90 | S, M, L, XL | 7 |
| Sheer Plus-Size Maid Costume | $9.90 | S, M, L | 3 |
| Strawberry Heart Print Cami Set | $9.90 | S, M, L, XL, 2XL | 1 |
| Lace Bow Two-Piece Lingerie Set | $9.90 | S, M, L, XL, 2XL | 3 |
Questions
Quick answers.
What is a sister size in bras?
What is a sister size?+
A size with a different band and a different cup letter that holds a similar cup volume.
Is 34C the same as 36B?+
They are often compared as sister sizes, but the fit differs. Try both if you are between bands.
Does sister sizing work for every bra?+
No. Cup shape, stretch and brand sizing vary. Use it as a starting point, not a rule.
Should I size up or down?+
If the band is tight, go up a band and down a cup; if it is loose, go down a band and up a cup.
Still unsure?
Send us your measurements.
Tell us the piece you are considering and the fit you want. We will compare it with the actual stock.