What is a 30O in Victoria's Secret?

Victoria's Secret cups run about a full cup small, so a standard US 30O usually needs a 30P there. If you already wear a 30O in Victoria's Secret, your size in a true-to-size brand is likely a cup smaller.

Which brands keep a 30O the same?

In true-to-size brands a US 30O stays a 30O: Wacoal, Panache, Bravissimo, Glamorise, b.tempt'd, Maidenform, Fantasie, Gossard, Pour Moi, PrimaDonna, Marie Jo, Anita, Goddess. Fit can still vary by style, so treat the label as the starting point.

Do UK brands size a 30O differently from US brands?

UK brands label cups in a different sequence above D (D, DD, E, F, FF, G), so the same letters can mean different volumes. In a true-to-size UK brand like Panache, a US 30O is a 30K; the band number stays the same.

What size replaces a 30O in brands that don't use cup sizes?

SHEFIT, Kindred Bravely, ENELL, Under Armour, Nike size by their own charts (XS-XL or numeric) instead of band/cup, so a 30O doesn't carry over directly. Start from each brand's chart with your underbust and bust measurements.

Size conversion

What Is a 30O in Other Brands?

Bra sizes are not standardized: the same label means different things brand to brand, so your 30O is a starting point, not a fixed size. A US 30O usually needs a 30P in Victoria’s Secret, maps to a 30K in a true-to-size UK brand like Panache, and stays a 30O in Wacoal.

Your 30O in Victoria's Secret

30P

Cups run a full cup small, so size up

Your 30O in Panache

30K

True-to-size UK sizing

Your 30O in Wacoal

30O

True to size, year after year

Every brand we track

Your 30O, brand by brand

Grouped by the sizing system each brand labels its cups in. Brands we stock link to their full lineup.

US-sized brands

Brand	How it runs	Your 30O →
ThirdLovein stock	cups run generous	30O
Wacoalin stock	true to size	30O
Glamorisein stock	true to size	30O
SHEFITin stock	-	Adjustable XS-6Luxe sizing rather than standard band/cup; size by the brand chart.
b.tempt'din stock	true to size	30O
Kindred Bravelyin stock	-	Uses XS-XXL nursing/maternity sizing rather than band/cup; size by the brand chart.
ENELLin stock	-	Uses numeric high-impact sizing (00-8) rather than band/cup; size by the brand chart.
Natori	cups run small	30O
Bali	band runs large	28O
Playtex	band runs large	28O
Maidenform	true to size	30O
Vanity Fair	band runs large	30O
Calvin Klein	band runs small	30O
Victoria's Secret	cups run small	30P
Brooks	band runs small	30O
Under Armour	-	Compression fit runs generous; XS-XL sizing rather than band/cup; size by the brand chart.
Nike	-	Generous fit; XS-XL sizing rather than band/cup; size by the brand chart.
Cacique	band runs large	30O
Torrid	band runs large	30O

UK-sized brands (cups run D, DD, E, F, FF, G...)

Brand	How it runs	Your 30O →
Panachein stock	true to size	30K
Bravissimoin stock	true to size	30K
Freyain stock	band runs small	30K
Elomiin stock	cups run generous	30K
Fantasiein stock	true to size	30K
Curvy Kate	band runs small	30K
Gossard	true to size	30K
Pour Moi	true to size	30K
Goddess	true to size	30K

EU-sized brands

Brand	How it runs	Your 30O →
Chantelle	cups run small	30N
Simone Perele	cups run small	30N
PrimaDonna	true to size	30N
Marie Jo	true to size	30N
Triumph	band runs large	30N
Anita	true to size	30N

Translations are guidance from cross-brand fit data, not a guarantee - fit also depends on breast shape and style. Cross-brand offset data v1-2026-05-28.

In stock now

Shop 30O now

Real bras we track in stock in 30O, with live prices.

Freya

Offbeat Side Support Bra: Rosehip

$68.00View →

Freya

Starlight Side Support Balcony Bra (J - O Cup): Caramel

$66.00View →

Freya

Starlight Side Support Balcony Bra (J - O Cup): Black

$66.00View →

Freya

Viva Side Support Bra: Lace Natural Beige

$66.00View →

Freya

Offbeat Side Support Bra: Natural Beige

$68.00View →

Freya

Offbeat Side Support Bra: Black

$68.00View →

Freya

Freya Fancies Balcony Bra (GG - K Cup): White

$64.00View →

Freya

Freya Fancies Balcony Bra (GG - K Cup): Natural Beige

$64.00View →

See every 30O bra in stock →

30O sister sizes

Sister sizes hold the same cup volume on a different band. If the 30O cup fits but the band doesn’t, try:

32N What are sister sizes?

Interactive

Try your own size

Not a 30O? Enter any size to see it in every brand. Your size never leaves your browser.

Brand Size Translator

Find your size across different brands

Your base size (US)

30O

Why sizes vary: Each brand uses different patterns, materials, and fit philosophies. A 34DD in Victoria's Secret fits differently than a 34DD in Panache.

ThirdLove

Half-cup sizing available; cups run slightly generous.

30O

Wacoal

True to size; consistent fit across decades.

30O

Panache

UK sizing; true to size, consistent year over year.

30K

Bravissimo

UK sizing, and its US site labels cups the UK way too (FF, GG, HH). Fit offsets not yet measured.

30K

Freya

UK sizing; bands run snug.

30K

Elomi

UK plus-size full-bust; cups run generous.

30K

Glamorise

US full-figure; true to size.

30O

SHEFIT

Adjustable XS-6Luxe sizing rather than standard band/cup; size by the brand chart.

30O

b.tempt'd

Wacoal-family fit DNA; runs true to US sizing, lighter construction.

30O

Kindred Bravely

Uses XS-XXL nursing/maternity sizing rather than band/cup; size by the brand chart.

30O

ENELL

Uses numeric high-impact sizing (00-8) rather than band/cup; size by the brand chart.

30O

Natori

Cups run small; consider sizing up.

30O

Chantelle

French sizing; cups run small.

30N

Bali

Bands run loose; consider sizing down.

28O

Playtex

Bands run large; size down in band.

28O

Maidenform

Generally true to size.

30O

Vanity Fair

Bands run slightly loose.

30O

Calvin Klein

Bands run slightly snug.

30O

Victoria's Secret

Cups run very small; size up a full cup.

30P

Fantasie

UK sizing; consistent fit.

30K

Curvy Kate

UK sizing; bands run firm.

30K

Gossard

UK sizing; classic fit.

30K

Pour Moi

UK sizing; budget-friendly.

30K

Simone Perele

French luxury; cups run small.

30N

PrimaDonna

Belgian luxury; true EU sizing.

30N

Marie Jo

Belgian; consistent fit.

30N

Triumph

German; bands slightly generous.

30N

Anita

German; strong post-surgery range.

30N

Brooks

Compression sports style; may run snug.

30O

Under Armour

Compression fit runs generous; XS-XL sizing rather than band/cup; size by the brand chart.

30O

Nike

Generous fit; XS-XL sizing rather than band/cup; size by the brand chart.

30O

Goddess

UK sizing; strong plus-size range.

30K

Cacique

Lane Bryant's brand; bands run generous.

30O

Torrid

Plus-focused; bands run large.

30O

Common questions

30O conversion questions

What is a 30O in Victoria's Secret?: Victoria's Secret cups run about a full cup small, so a standard US 30O usually needs a 30P there. If you already wear a 30O in Victoria's Secret, your size in a true-to-size brand is likely a cup smaller.
Which brands keep a 30O the same?: In true-to-size brands a US 30O stays a 30O: Wacoal, Panache, Bravissimo, Glamorise, b.tempt'd, Maidenform, Fantasie, Gossard, Pour Moi, PrimaDonna, Marie Jo, Anita, Goddess. Fit can still vary by style, so treat the label as the starting point.
Do UK brands size a 30O differently from US brands?: UK brands label cups in a different sequence above D (D, DD, E, F, FF, G), so the same letters can mean different volumes. In a true-to-size UK brand like Panache, a US 30O is a 30K; the band number stays the same.
What size replaces a 30O in brands that don't use cup sizes?: SHEFIT, Kindred Bravely, ENELL, Under Armour, Nike size by their own charts (XS-XL or numeric) instead of band/cup, so a 30O doesn't carry over directly. Start from each brand's chart with your underbust and bust measurements.

Shop every 30O bra Translate any size How sizing differs by brand