FR to US conversion

FR 100E in US Bra Size

Convert 100E from French sizing to US sizing, with the full international table, sister sizes, and practical fit checks in one place.

Instant answer

100E (FR) =

38DD US

In this sizing table, 100E in French sizing converts to 38DD in US sizing.

Full conversion table for 100E (US 38DD)

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

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

What this conversion means

If you are shopping from a French size chart, use 38DD as the closest US starting label for 100E. This is still a label translation, so brand grading, fabric, and wire shape can change the final fit.

Sister sizes for the US equivalent (38DD)

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

What measurements make a 100E?

100E starts with the underbust, then adds cup depth from the bust measurement. In the current calculator formula, the closest starting range is about 37-39 inches (94-99 cm) under the bust and about 42.5-43.5 inches (108-110 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. This page uses 38DD as the US equivalent for those measurement notes.

Is 100E big or small?

The label 100E can look more dramatic than it fits, especially across systems. In this size set, the US equivalent uses a fuller band and a fuller 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 100E 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 100E differs between brands

Brand sizing matters for 100E because cup depth, wire width, and band stretch are design choices. 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 100E

A good shopping path for 100E starts with everyday support, then moves into outfit-specific shapes. 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 100E the same as 38DD in the US?

In this dataset, 100E (FR) converts to 38DD in US sizing. Some brands publish their own charts, so use this as the closest standard label and still check the real fit.

What is 100E in UK sizing?

100E (FR) matches the same base record as 38DD (UK). The full table on this page shows each supported label side by side.

How do I check the fit of 38DD?

A good US fit should feel secure without digging. If 38DD feels close in the cup but wrong in the band, compare the sister sizes before changing cup volume.

What sister sizes work with 38DD?

36DDD and 40D are the closest sister-size options for 38DD 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?

Bra labels are written differently across US, UK, EU, French, and Australian systems. Cup letters can also diverge after D, so a converted label is a starting point rather than a promise of identical fit.

What measurements usually make 100E?

100E maps to US 38DD here. The current calculator formula points to about 37-39 inches underbust and 42.5-43.5 inches bust, or roughly 94-99 cm and 108-110 cm. Treat that as a starting range and then check the real fit.