US to UK conversion

38A in UK Bra Size

Convert 38A from US sizing to UK sizing, with the full international table, nearby sister sizes, and fit checks in one place.

Instant answer

38A (US) =

38A UK

In this sizing table, 38A in US sizing converts to 38A in UK sizing.

Sizing varies by brand

A conversion gives you the closest label in another sizing system, but brands can grade cups, wires, and bands differently. Use the converted size as a starting point, then check the retailer's chart and the fit of the actual bra.

Before you buy in UK sizing

Use 38A as the translated label, not as a fit guarantee.
Check the retailer's size chart because some brands grade bands and cups differently.
If the cup volume feels close but the band changes, compare sister sizes before switching cup letters.
When possible, check return rules before buying across sizing systems.

Full conversion table for 38A

38A bra size conversion across US, UK, EU, French, and Australian sizing.
US	UK	EU	FR	AU
38A	38A	85A	100A	16A

Bra sizing varies between brands. Use this as an accurate starting point and check the fit.

Sizes near 38A in UK sizing

If 38A is close but not right, these are the neighbouring US sizes and what each one becomes in UK sizing. Band neighbours change the fit around the ribcage; cup neighbours change volume.

US sizes adjacent to 38A and their UK equivalents.
US size	UK size	How it differs
36A	36A	One band step snugger, same cup letter.
40A	40A	One band step looser, same cup letter.
38B	38B	One cup step up, same band.

What this conversion means

A US 38A means a 38 band with a A cup step. The UK equivalent in this table is 38A, which keeps the same general fit target but uses UK labeling. If the cup feels close and the band feels off, sister sizing is usually the next thing to try.

Sister sizes for 38A

Sister sizes: 36B can be worth checking when the cup volume feels close but the band needs a different feel.

What measurements make a 38A?

A size like 38A makes more sense when the two tape measurements are shown side by side. In the current calculator formula, the closest starting range is about 37-39 inches (94-99 cm) under the bust and about 38.5-39.5 inches (98-100 cm) around the fullest part of the bust. The band comes from the underbust rounding, while the cup step comes from the difference between bust and band.

Is 38A big or small?

38A should be treated as a fit label, not as a judgement about body size. In this size set, the US equivalent uses a fuller band and a lower cup step. Cup letters are relative to the band, so a D on one band is not the same volume as a D on every other band. The most useful question is whether the band stays level and the cups hold smoothly, not whether the label sounds large or small.

If 38A doesn't fit right

Band rides up: The band may be too loose or stretched out; try a snugger band or compare the snugger sister size.

Cups gape: The cup may be too roomy, too deep, or pulled away by a loose band; check the band before changing cup volume.

Cups spill: The cup volume may be too small or the cup shape may be too closed; try one cup step up before changing the band.

Straps dig in: The straps may be compensating for a band that is not supporting enough; reset the band fit before tightening straps.

How 38A differs between brands

Use 38A as the starting label, then let the individual brand chart narrow the choice. A firmer elastic can make the same band feel smaller, and a shallow or narrow cup can make the same cup letter feel different. Check the retailer chart, read fit notes when available, and compare the label against the brand and region sizing guide before treating the conversion as final.

Shopping for 38A

Treat 38A as your anchor size while you compare cup shape, strap placement, and band feel. If the cup is in a lower or middle step, lightly lined T-shirt styles can make gaps easy to spot. Fuller cup steps often benefit from styles with steadier side support, deeper cups, or a balconette shape depending on breast shape. For special outfits, compare the fit needs in the outfit guides before choosing a strapless, plunge, or backless option.

Bras in your size

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Everyday Fit Store

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Comfort Band Co.

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Soft Cup Edit

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FAQ

Is 38A in the US the same as UK sizing?

The closest UK label here is 38A. It is a conversion guide, so retailer charts and try-on fit still matter.

What is 38A in Australian sizing?

In this same table, 38A converts to 16A (AU). That helps when a retailer shows a Australian chart instead of a UK one.

How do I know if 38A fits?

Start with the band: it should feel firm and even around your ribcage. Then check cup containment and comfort across the style you are actually trying on.

What sister sizes work with 38A?

36B are the closest sister-size options for 38A in this dataset. Try a sister size when cup volume feels close but the band needs to feel snugger or looser.

Why do bra sizes differ between countries?

Countries and brands do not all use the same band labels or cup-letter sequence. A conversion translates the closest standard label, but the final fit still depends on the specific bra.

What measurements usually make 38A?

The current calculator formula points to about 37-39 inches underbust and 38.5-39.5 inches bust, or roughly 94-99 cm and 98-100 cm. Treat that as a starting range and then check the real fit.