What to look out for
Sister sizes for 70B: 65C, 75A. If 70B holds well around the band but the cup digs in or gapes, reach for a sister size instead of changing only the letter — cup volume stays similar while the band changes.
Worth checking too
At this cup size, padded and push-up models work well because they add volume, as do smooth cups under fitted clothes.
Delivery and returns
Remember that size grids differ between brands — we publish the manufacturer's chart with every product. We have explained how to measure on our How to find your size page. Parcel locker delivery is PLN 12.99, free from PLN 199, and you have 14 days to return.
More about this category
Size 70B means an underbust measurement of about 68-72 cm and a difference between the bust and underbust measurements of around 13-15 cm. The band here is narrow, so it is the band that decides all the support - if, fastened on the middle hook, it pulls away from your back by more than two fingers, the bra is too big in the band.
At this size the underwire should end just beyond the underarm line and lie flat against the ribs, never on breast tissue. If the band rides up at the back, shortening the straps will not usually help - that is a signal you need a tighter band. The sister sizes for 70B are 65C and 75A: the same cup volume, a different band.
Before you order, measure yourself with a soft tape against bare skin, standing upright, and compare the result with our size guide. Two models in the same size can fit differently, because underwire curvature and cup depth vary.
This collection is dominated by models from Italian and Polish manufacturers, among them Sielei, Lormar and Selene. You will find both smooth moulded cups for fitted blouses and lace models for sets. If you are after a style rather than a specific size, go to balconette bras or wire-free models.
How many centimetres is a band size of 70 in a bra?
An underbust measurement of about 68-72 cm, taken directly under the bust with the tape parallel to the floor.
What are the sister sizes for 70B?
65C and 75A. They have the same cup volume and differ in the band.
The band rides up at the back - what should I do?
That usually means the band is too big. Try a smaller band with a bigger cup, that is 65C instead of 70B.
Which hook should I fasten a new bra on?
The loosest one. The remaining rows are for shortening the band once the fabric stretches after a few months of wear.
