Which style to choose
Sister sizes for 70C: 65D, 75B. If 70C 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.
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.
Washing and care
The number 70C describes an underbust measurement of around 70 centimetres and a cup whose volume corresponds to a difference of roughly fifteen centimetres. A narrow band means more work for the band itself: at 70 it is the band, not the straps, that has to carry the weight, which is why it should sit snugly and run level across the back.
Fabrics and comfort
In this collection the size 70C appears in very different constructions, from moulded foam cups through lace models with a horizontal seam to soft bralettes. At smaller bands the differences between them are easy to feel, because a shorter band signals sooner that the construction has been badly chosen.
The most common mistake at this size is reaching for a bigger band when the underwire digs in. Pressure under the arm almost always comes from too shallow a cup rather than too tight a band, so the answer is to go up a letter while keeping the 70. The second typical symptom is slipping straps, which mean the band is too loose and starting to travel up the back.
The sister size with a similar cup volume is 75B. If you need a deeper cup on the same band, check 70D. We have explained how to measure step by step on our bra sizing page. On a first purchase in this size it is worth taking two models with different cup constructions and comparing them after a few hours of wear.
What does size 70C mean?
An underbust measurement of about 70 cm and a cup corresponding to a difference between measurements of roughly 15 cm.
What should I do if the underwire digs in under my arm?
Usually you need a deeper cup, that is 70D, rather than a wider band.
Which size is the sister size for 70C?
75B has a similar cup volume on a wider band.
Why do my straps slip?
Most often because the band is too loose and rides up the back.
