Why your size changes between brands, and between EU and UK

If you have ever worn a 75B in one shop and a 75C in another, you are not measuring wrong. Bra sizing is a starting point, and it is not standardised the way a shoe length is. Here is why sizes vary, and how to shop with that in mind.

Why sizes differ between brands

• Cut and cup shape: a shallow cup and a deep cup can both be labelled the same size.
• Fabric and stretch: lace, cotton and microfibre stretch differently, and stretchy bands run looser.
• Style: a plunge, a balconette and a full-coverage bra each sit differently on the same body.
• Brand sizing charts: brands set their own charts, and they do not always match.

EU and UK sizing

Both use a band measurement and a cup letter, but they write them differently. EU bands are in centimetres, in steps of 5. UK bands are in inches, in steps of 2. Cup letters match up to D, then differ.

• EU 65 is about UK 30, 70 is 32, 75 is 34, 80 is 36, 85 is 38, and 90 is 40.
• Cups A, B, C and D are the same in both systems.
• After D, the EU letters continue E, F, G, while UK sizing goes DD, E, F. So EU E is UK DD, and EU F is UK E.

For example, 75E in EU sizing is about 34DD in UK sizing. Our size finder shows both.

Your own size changes too

Bodies change over months and years, and that is normal. Weight changes, hormones, pregnancy and breastfeeding can all shift your size. It is worth measuring again from time to time, or whenever a bra you liked stops fitting.

How to shop with all this in mind

1. Start from your measured size and read the brand's own size chart.
2. Check whether the style has stretch, and how it is described.
3. If a size is close but not right, try the sister size.
4. Judge fit by how the bra sits, not by the number on the label.