Is a 30K the same in every brand?

No - a 30K isn't identical across brands, because brands use different sizing systems and cup depths. Here's how a standard US 30K translates in the brands we track: ThirdLove 30K, Wacoal 30K, Panache 30H, Freya 30H, Elomi 30H, Glamorise 30K, b.tempt'd 30K, Fantasie 30H. SHEFIT, Kindred Bravely, ENELL size by their own chart instead of band/cup.

What are the sister sizes for 30K?

30K's sister sizes — same cup volume, different band — are 28L and 32J. Try a sister size if the band feels too tight or loose but the cup still fits.

30K Bras

What is a 30K in other brands?

343 bras tracked in 30K · 4 brands · See all K cup

Brands: Bravissimo, Fantasie, Freya, Panache

Your 30K across brands

A 30K isn’t the same in every brand. Here’s how a standard US 30K translates across the brands we track — and how each one runs.

Brand	How it runs	Your 30K →
ThirdLove	cups run generous	30K
Wacoal	true to size	30K
Panache	true to size	30H
Freya	band runs small	30H

What is a 30K in other brands? See all 30+ brands →

Editorial buying guide

Read the 30K buying guide

Top picks, sister sizes, and how to spot a good 30K fit.

Read →

Sister sizes

28L 32J What are sister sizes?

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Your 30K across brands

Envy Full Cup Bra - Chai

Envy Full Cup Bra - Chestnut

Envy Full Cup Bra - Teal

Allure Full Cup Bra - Forest Green

Jennifer Plunge Bikini Top - Aurora Red

Allure Demi Balcony Bra - Champagne Gold

Naomi Nursing Bra - Noir

Eva Balcony Tankini Top - Sicily Print

Anya Riva Balcony Tankini Top - Black

Marlene Balcony Bra - Black

Etta Bra - White Multi

Freya Flirt Padded Half Cup Bra: Pink Frost

Freya Flirt Padded Half Cup Bra: Black

Mykonos Plunge Swimsuit - Teal

Florence Bra - White/Lime

Paloma Balcony Swimsuit - Black Sand Print

Paloma Balcony Swimsuit - Flutter Print

Quinn Plunge Bra: Cameo

Quinn Plunge Bra: Black

Melrose Bra - White

Melrose Bra - Beige

Entwined Plunge Bra: Tattoo

Tango Essence Balcony Bra - Honey

Tango Essence Balcony Bra - Black

Etta Bra - Multi

Niya Bra - Leopard Print

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

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

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

Blossom Balcony Bra - Taupe

Blossom Balcony Bra - Black

Offbeat Padded Half Cup Bra: Black

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

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

Viva Side Support Bra: Lace Natural Beige

Posie High Apex Bra: White

Entwined Molded Bra: Tattoo

Entwined Plunge Bra: Daisy

Laurine Plunge Bra: Raspberry

Love Crush Plunge Bra: Aqua Haze

Tailored High Apex Bra: Dark Sapphire

Loveland Plunge Bra: Bombshell Teal

Freya Fancies Longline Bra: White

Freya Fancies Longline Bra: Black

Envisage Full Cup Side Support Bra: Evening Blue

Blossom Balcony Bra - Celeste

Tango Edit Balcony Bra - White

Clara Full Cup Bra - Black/Pink

Martha Bra - Blue Multi

Willow Bra - Lilac/Multi

Delilah Bra - Blue Floral

Anya Riva Spot Balcony Swimsuit - Navy/Vanilla

Offbeat Side Support Bra: Rosehip

Offbeat Side Support Bra: Natural Beige

Offbeat Side Support Bra: Black

Tailored High Apex Bra: Natural Beige

Tailored High Apex Bra: Black

Loveland Plunge Bra: Bombshell Black

Smoothing Molded Bra: Nude

Smoothing Molded Bra: Black