Mirabella Padded Swim Bra: Sizing Guide for a 70 Band
By Nessa | Published: 2026-11-03
Category: Buying Guides
Learn how the Mirabella padded swim bra fits a 70 band, why the sizing runs large, and how to choose the right cup for medium to large busts.
Quick answer
Choose one size smaller than your usual band size in the Mirabella padded swim bra, because its sizing runs large. For a 70 band, that usually means trying a 65 band first, then adjusting the cup to keep the T-shaped seams lifting and rounding your bust naturally.
Why the 70 band feels different from your everyday bra
Swim bras are built to stay put when wet, so the band often feels firmer than a lingerie bra in the same size. The Mirabella uses classic underwires plus side underwires, which adds structure around the ribcage. If you normally wear a 70 band in lingerie, that extra structure plus the brand's larger sizing can make the 70 feel loose rather than supportive.
The padded cups are cut with one horizontal and one vertical seam. That shape is designed to lift and round medium to large busts without flattening them, but it only works when the band holds the cups close to your body. A band that slides down at the front is the clearest sign you need to size down.
The trade-off: smaller band, different cup feel
Sizing down fixes band slack but changes how the cups sit. A tighter band pulls the underwires closer to your breastbone, so the same cup letter can feel fuller. If you are between cup sizes, stay with the cup that matches your bust volume and let the smaller band do the work. If the smaller band digs in under the arms, the cup is probably too small rather than the band being wrong.
Because the Mirabella is a padded bikini top rather than a soft swim bra, it offers more shape but less stretch. That makes the initial fit check more important than with unpadded styles: once the band and cup are right, the top stays consistent in and out of the water.
Decision rules for choosing your Mirabella size
- Start with the band: If you usually wear a 70 band, try a 65 first. The Mirabella's sizing is intentionally generous, and the side underwires keep a smaller band from feeling too tight. Measure your underbust snugly before ordering; do not rely on your lingerie band size alone.
- Match the cup to your bust volume: Keep the cup size that fits your bust in your usual bra. A smaller band can make the same cup feel slightly fuller, so avoid sizing up in the cup unless you are clearly spilling over.
- Check the lift test: Put the top on and raise your arms. If the band rides up at the back or the front edge lifts away from your ribcage, go down another band size or tighten the back closure if available.
- Decide between 70 and 65: Choose the 70 only if your underbust measures closer to 75 cm and you prefer a relaxed band for lounging. Choose the 65 if you want secure support for swimming and the band currently slides. If neither feels right, the cup shape may be the issue rather than the band; check that the horizontal seam sits across the fullest part of your bust.
Product facts
- Mirabella padded - Biustonosz - 70: Sizing runs large, so the brand recommends choosing a smaller size. Start one band size below your usual 70 and check the fit before committing.
Mirabella padded - Biustonosz - 70
Who the Mirabella 70 band suits
Best for
- Swimmers with medium to large busts who want a padded, lifting bikini top
- Anyone whose usual 70 band feels slightly loose in other swimwear
Not for
- Shoppers who want a soft, unpadded swim bra with maximum stretch
- Those who prefer a relaxed band and do not need underwire support
