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Buying guide · US 40A

The Best Bras for 40A

A 40A is stocked almost everywhere: 32 of our 49 charted brands cut it, which moves the question from availability to judgment. Start with the picks below, then use the full computed table to compare how every brand labels and positions your size, and choose by construction for a fuller band with a proportionally shallow cup.

One size, every label

40A in every system

US 40AUK 40AEU / DE 90AFR / ES 105AAU / NZ 18AIT 6ªAJP B90

Cup letters diverge above D, so the letter changes even though the bra does not. Convert by position, and match the printed tag in the table below.

Start here

Strong first tries at 40A

These are chosen by rule, not payment: your size sits inside each chart, away from its edges. The complete computed list follows.

Computed, not sponsored

The complete list: who makes 40A

BrandSystemTheir label for itRange positionInteractive chart
ThirdLoveUS40Awell in rangechart →
AerieUS40Aat chart edgechart →
AmoenaEU90Aat chart edgechart →
AnitaEU90Aat chart edgechart →
Auden (Target)US40Aat chart edgechart →
BendonAU18Aat chart edgechart →
BerleiAU18Aat chart edgechart →
Boux AvenueUK40Aat chart edgechart →
Bras N ThingsAU18Aat chart edgechart →
ChantelleFR105Aat chart edgechart →
CuupUS40Aat chart edgechart →
EtamFR105Aat chart edgechart →
GossardUK40Aat chart edgechart →
Harper WildeUS40Aat chart edgechart →
HunkemöllerEU90Aat chart edgechart →
KnixUS40Aat chart edgechart →
Le MystèreUS40Aat chart edgechart →
M&SUK40Aat chart edgechart →
MaidenformUS40Aat chart edgechart →
Marie JoEU90Aat chart edgechart →
NatoriUS40Aat chart edgechart →
PepperUS40Aat chart edgechart →
Savage X FentyUS40Aat chart edgechart →
Shock AbsorberUK40Aat chart edgechart →
Simone PérèleFR105Aat chart edgechart →
SkimsUS40Aat chart edgechart →
SomaUS40Aat chart edgechart →
TriumphEU90Aat chart edgechart →
Triumph JapanEU90Aat chart edgechart →
Victoria’s SecretUS40Aat chart edgechart →
WacoalUS40Aat chart edgechart →
Wacoal JapanEU90Aat chart edgechart →

Of the 32: 1 carry 40A well inside their chart, 31 at its edge. Well in range means the size sits inside the brand's chart, cut from a block graded around it. At chart edge means it is the first or last size they make, which is real but drafted at the limit of their grading. Your measured size guide: the universal 40A page.

Check first

Is 40A actually your size?

Snug underbust, relaxed bust. Tap the unit to switch inches and centimeters.

Same published math as the calculator: snug measure, no added inches.

Choosing well

How to choose at 40A

40A pairs a larger band with modest cup depth, a proportion the industry underserves in the opposite direction from full-bust sizes: bands go up but the assumed cup depth climbs with them, leaving shallow-cup wearers with cups that wrinkle at the top.

Look for stretch-top cups, lightly lined or unlined styles, and wireless constructions with structured bands. At this proportion the band delivers the support and the cup mostly needs to follow the profile without excess fabric.

Brands whose plus-band ranges start rather than end at your band tend to grade the shallow letters more honestly there.

Watch for: Wrinkling at the top of the cup here usually means the profile, not the letter. Try a stretch-edge cup before sizing the letter down and losing base volume.

Styles that earn it

Constructions that work for a fuller band with a proportionally shallow cup

Each guide explains the construction, who it flatters and its honest trade-offs.

Same volume, different band

Sister sizes for 40A

A sister size keeps identical cup volume on a different band. If the 40A band rides up or digs in while the cup fits, the sister is the fix.

Answered

40A bras, answered

Which brands make a 40A bra?

Of the 49 brands whose published size charts we track, 32 cut a 40A. The strongest first tries: ThirdLove. The full table on this page lists every one in the brand's own notation, converted by chart position.

What is 40A in other sizing systems?

US: 40A. UK: 40A. EU / DE: 90A. FR / ES: 105A. AU / NZ: 18A. IT: 6ªA. JP: B90. Letters diverge above D, so always convert by position, not by letter.

What styles work best for 40A?

For a fuller band with a proportionally shallow cup: Wireless with structure, Unlined, T-shirt, Front-close, Longline bralette. Wrinkling at the top of the cup here usually means the profile, not the letter. Try a stretch-edge cup before sizing the letter down and losing base volume.

Ready to shop

Multi-brand retailers with deep size ranges

Shop links may earn a commission; your price does not change, and commissions never touch the computed tables above. How this site makes money. HauteFlair shares ownership with this site, disclosed here.

Shop itAt HauteFlair, our sister retailer

HauteFlair labels cups in UK letters, so these links already convert your size by position (a US DDD lands on a UK E, a US G on a UK F). HauteFlair is owned by the same company as Brasize.ai; that relationship never changes the sizing math, charts, or fit advice on this page. How this site makes money.

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