Is a 40K the same in every brand?

No - a 40K isn't identical across brands, because brands use different sizing systems and cup depths. Here's how a standard US 40K translates in the brands we track: ThirdLove 40K, Wacoal 40K, Panache 40H, Bravissimo 40H, Freya 40H, Elomi 40H, Glamorise 40K, b.tempt'd 40K, Fantasie 40H. SHEFIT, Kindred Bravely, ENELL size by their own chart instead of band/cup.

What are the sister sizes for 40K?

40K's sister sizes — same cup volume, different band — are 38L and 42J. Try a sister size if the band feels too tight or loose but the cup still fits.

40K Bras

What is a 40K in other brands?

349 bras tracked in 40K · 7 brands · See all K cup

Brands: Bravissimo, Elomi, Fantasie, Freya, Glamorise, Panache, Wacoal

Your 40K across brands

A 40K isn’t the same in every brand. Here’s how a standard US 40K translates across the brands we track — and how each one runs.

Brand	How it runs	Your 40K →
ThirdLove	cups run generous	40K
Wacoal	true to size	40K
Panache	true to size	40H
Bravissimo	true to size	40H

What is a 40K in other brands? See all 30+ brands →

Editorial buying guide

Read the 40K buying guide

Top picks, sister sizes, and how to spot a good 40K fit.

Read →

Sister sizes

38L 42J What are sister sizes?

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Your 40K across brands

Millie Bra - Cocoa

Millie Bra - Mint

Millie Bra - Ivory

Satine Bra - Champagne

Ultimate Comfort Bra - Burgundy

Ultimate Smoothing Balconette Bra - Blush

Millie Bra - Black

Millie Bra - Bright Blue

Amelia Flourish Bra - Blue Multi

Millie Bra - Neon Coral

Amelia Floral Bra - Multi

Millie Bra - Ivory

Millie Floral Bra - Sage Green

Millie Bra - Purple

Millie Bra - Caramel

Ultimate Comfort Bra - Dusky Blue

Ultimate Comfort Bra - Black

Millie Bra - Neon Pink

Ultimate Comfort Bra - Blush

Millie Floral Bra - Heather

Millie Bra - Blush Pink

Millie Bra - Denim Blue

Esme Balcony Bra - Mocha Animal

Esme Balcony Bra - Black Animal

Ana Nursing Bra - Vintage

Lauren Plunge Bikini Top - Black

Lauren Plunge Bikini Top - Cobalt

Amara Full Cup Bra - Honey

Amara Full Cup Bra - Black

Lauren Plunge Bikini Top - Red

Freedom Non Wired Sports Bra - Black/Chalk

Apollo Sports Bra - Lilac

Apollo Sports Bra - Teal/Pink

Una Bra - Cornflower Blue

Hettie Bra - Beige

The Shoulder Ease Bra - White

Hettie Bliss Bra - Black Multi

Lacey Bra - Cobalt

Lacey Floral Bra - Cobalt

Nursing Ultimate Comfort Bra - Dusky Blue

Esi Bra - Red Multi

Esi Bra - Pink Multi

Hettie Bra - Blue / White

Esi Bra - Denim Blue

Lacey Blossom Bra - Lilac

Una Bra - Blush Pink

Lacey Bra - Fuchsia

The Shoulder Ease Bra - Black

Hettie Bra - Black

Hettie Bra - White

Nursing Ultimate Comfort Bra - Black

Lacey Bra - Beige

Lacey Bra - Black

Lacey Bra - White

Hettie Bliss Bra - Hot Pink

Power Wired Sports Bra - White

Endurance Wired Sports Bra - Black

Power Wired Sports Bra - Latte

Endurance Wired Sports Bra - Dusty Rose

Entice Full Cup Bra - Red