US to UK conversion

38B in UK Bra Size

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

Instant answer

38B (US) =

38B UK

In this sizing table, 38B in US sizing converts to 38B 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 38B 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 38B

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

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

Sizes near 38B in UK sizing

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

What this conversion means

This page answers the specific 38b in uk conversion using the site's shared sizing data. 38B is the UK label for 38B here, and the table above keeps the other supported systems together for quick comparison.

Sister sizes for 38B

Sister sizes: 36C and 40A can be worth checking when the cup volume feels close but the band needs a different feel.

What measurements make a 38B?

For 38B, the band number gives the ribcage anchor and the cup describes the bust difference. In the current calculator formula, the closest starting range is about 37-39 inches (94-99 cm) under the bust and about 39.5-40.5 inches (100-103 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 38B big or small?

38B sits in context only when the number and letter are read as a pair. 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 38B 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 38B differs between brands

A conversion points you to a label, but a brand chart tells you how that maker expects 38B to fit. 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 38B

For 38B, practical shopping is less about one perfect style and more about reading the fit quickly. 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

Placeholder for a broad size range and return-friendly basics.

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Comfort Band Co.

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Soft Cup Edit

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FAQ

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

Not exactly. 38B is the US label, and this table converts it to 38B in UK sizing, though some brands publish their own charts.

What is 38B in European sizing?

In this same table, 38B converts to 85B (EU). That helps when a retailer shows a European chart instead of a UK one.

How do I know if 38B fits?

Check that the band stays level, the cups do not spill or gap, and the center gore sits close if the bra has wires. If the cup feels right but the band feels wrong, try a sister size.

What sister sizes work with 38B?

36C and 40A are the closest sister-size options for 38B 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 38B?

The current calculator formula points to about 37-39 inches underbust and 39.5-40.5 inches bust, or roughly 94-99 cm and 100-103 cm. Treat that as a starting range and then check the real fit.