34H Bra Size
Everything you need to know about bra size 34H — measurements, sister sizes, international equivalents, and fit advice.
Last reviewed on 28 April 2026.
Measurements for 34H
34H is built for an underbust ribcage measurement that falls in the 33–35 inch range, with a full-bust measurement around 43 inches. The band number — 34 — is one of the most widely produced band sizes, with broad style choice. The cup letter — H — describes the difference between the two measurements; an H cup means the full bust is about eight inches larger than the underbust — well-engineered bands and reinforced wires are typically what hold a bra steady for a full day at this size.
34H in Other Sizing Systems
EU and FR sizing read the band in centimetres, which is why 34H maps to 75H and 90H respectively — the same body, expressed in different units. AU sizing uses a small numeric scale (12FF for this band). UK sizing shares the band number with the US but parts ways at the cup once you go past D, so 34H reads as 34FF on a UK label.
Sister Sizes for 34H
These sizes have the same cup volume as 34H. Try them if the band feels too tight or too loose.
← Tighter band, bigger cup · Looser band, smaller cup →
Sister sizes are useful when the cup of your 34H fits well but the band is wrong — too loose by the end of the day, or too tight to clip up comfortably. Going one band smaller and one cup larger keeps the cup volume the same while tightening the band; going the other way loosens the band without losing cup space. Read the full sister-size matrix if you want to see how this works for every size at once.
Fit Tips for 34H
H cups call for maximum-support construction: reinforced bands, wider straps, and side panels. Specialist fuller-bust ranges are usually the most reliable source of styles in this cup.
If your 34H bra is gapping at the top of the cup, the cup may be too large or the wrong shape — try a demi-cup or balconette before assuming the size is wrong. If the centre piece between the cups (the gore) does not lay flat against your sternum, the cup is almost certainly too small; go up one cup. If the band rides up across your back during the day, the band has stretched out or was too loose to begin with — drop one band size and add one cup to keep the same cup volume.
For more detailed troubleshooting, the Fit Test on the home page covers six common visible problems and the size or shape change that usually addresses each one. The guide to measuring mistakes covers the most common reasons a calculation comes out wrong in the first place.
Related sizes
If 34H is close but not quite right, these neighbouring sizes are the most useful next places to look:
Not sure about your size? Measure yourself and double-check.
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