UK · US · EU Bra Sizing

Find the bra size that actually fits.

Most women have worn the wrong size without knowing it. Get yours right in under a minute, with measurements that stay on your device.

Choose your preferred units
in
in

Measure snugly over a non-padded bra. Keep the tape level.

Your size
US
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UK
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EU
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Sister sizes to try
The system you currently know your size in
in

Common UK bands: 28, 30, 32, 34, 36, 38, 40, 42, 44, 46.

Equivalent sizes
UK
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US
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EU
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How to Measure

A tape measure and two minutes.

Accurate measurements are the foundation of a good fit. Most fitting frustration comes from skipping these basics.

  1. Wear an unpadded bra

    Or measure with no bra at all. Padding adds inches and skews the result.

  2. Measure your underbust

    Wrap the tape directly under your bust. Keep it firm, snug, and parallel to the floor.

  3. Measure your full bust

    Across the fullest part. Tape should be level, not pulled tight or drooping.

  4. Stand naturally

    Don't hold your breath or arch your back. Relaxed posture gives the truest reading.

Two figures showing how to measure: tape placed firmly under the bust for the band measurement, and tape placed across the fullest part of the bust for the bust measurement.
Why It Matters

A small thing that changes everything.

The right bra is invisible. It disappears into your day. The wrong one is a slow, persistent annoyance most women never realise they're tolerating.

Most

Have worn the wrong size

Fitting research consistently finds that many women wear a band too loose, a cup too small, or both, often for years without realising.

2–3 sizes

Common mismatch

Most ill-fitting bras are off by a band size and a cup size. The fix is rarely going up. It's usually band down, cup up.

1×

Year between fittings

Body shape shifts. Bands stretch. Even with no weight change, last year's perfect bra may not be this year's. Re-measure annually.

Common Questions

Things people often ask.

Above DD, the two systems diverge. UK uses E, F, FF, G, GG, H, HH, J, JJ, K. US typically uses DDD, then jumps to G, H, I, J, K. The cup volume is identical at the same step; only the letter changes.
Sister sizes have the same cup volume but different bands. If your calculated size feels close but not perfect, try going down a band and up a cup, or up a band and down a cup. It's often how a great fit is found.
Probably not in the way you think. The most common mistake is wearing too large a band, which forces you into too small a cup. The band should feel firm and stay level when you raise your arms. If the cups feel small, try going down a band and up a cup, which is your sister size up.
Every six to twelve months, or any time your weight changes noticeably, after pregnancy, after starting hormonal birth control, or during perimenopause. Body shape changes more than people expect.
Cup shape, wire width, gore height, and strap placement all vary between brands and even between styles within a single brand. Your measured size is a starting point; a brand's specific fit notes and reviews tell you the rest.
No. All calculations happen in your browser. Nothing is sent to a server, logged, or saved.

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