Bra Size Calculator

Side Boob Spillage Fix

Contain breast tissue comfortably with accurate measurements, supportive styles, and the scoop-and-swoop method.

Recheck My SizeDownload Side Support Checklist

How to Identify Side Spillage

These signs indicate your bra needs more cup depth, better wire alignment, or supportive wings.

  • Breast tissue escaping near the underarm within an hour of wearing the bra
  • Cup seams pressing into tissue, creating bulges or discomfort
  • Underwire sitting on top of tissue instead of following the breast root
  • Bra feels supportive when first put on but shifts during the day

Quick diagnostic tip

Trace the underwire with your finger. It should sit behind breast tissue, not on top of it. If you feel tissue outside the cup, try a wider wire or a different cup shape.

Reconfirm Your Measurements

Cup depth and wire shape rely on precise measurements. Take a moment to re-measure before making size changes.

  1. Re-measure your band snugly to ensure it is doing most of the support work.
  2. Measure bust circumference when leaning forward to capture the fullest tissue distribution.
  3. Enter the measurements into the calculator and note cup size differences.
  4. Review how your current bra compares to the calculator result and adjust accordingly.
Review Measurement GuideOpen Calculator

Adjust Wire Shape & Cup Volume

Match wire width to breast root

If underwires sit on tissue, look for wider wires or go up a cup while maintaining band support.

Consider taller side wings

Bras with reinforced wings or side slings keep tissue forward and contained.

Test sister sizes carefully

Going up a cup can offer more depth; pair it with a smaller band if the current band is loose.

Styles That Support the Sides

Side support bras

Inner slings and panelled cups push tissue forward, reducing side overflow.

Full coverage or high apex bras

Provide taller cup fabric to contain soft or fuller side tissue.

Minimizers with structured wings

Compress evenly and offer wider wings for a smooth silhouette.

Supportive bralettes (wireless)

Stretch fabrics adapt to daily fluctuations, ideal for relaxed days or postpartum comfort.

Master the Scoop & Swoop

This technique helps position tissue inside the cup and reduces overflow during daily movement.

  1. Lean forward and place your hand in the cup on the same side.
  2. Gently sweep all tissue from the underarm toward the center of the cup.
  3. Lift the strap slightly with your other hand to guide tissue fully into the cup.
  4. Repeat on the other side, then adjust straps so cups sit flush.

Video coming soon

We are producing short demo clips to show scoop-and-swoop from multiple angles. Save this page and check back soon for visual guidance.

Plan for Body Changes

Tip

Strengthen back and posture muscles to reduce downward pressure on bands.

Tip

Rotate bras with strong side panels to rest tissues between wears.

Tip

For postpartum or hormone fluctuations, keep a flexible cup option on hand.

Keep Exploring Fit Solutions

Side support is part of an overall fit. Explore these guides to fine-tune the rest of your bra wardrobe.

Fill cup space with targeted adjustmentsAnchor your band so cups stay alignedNavigate postpartum changes with supportive styles

Tell us what you need

We are curating a list of brands and specialists that excel at side support. Share your requests so we can prioritise what matters most to you.

Contact the team

Frequently Asked Questions

Is side spillage normal during postpartum or weight changes?

Yes, fluctuations are common. Keep stretch-friendly styles (bralettes, wireless bras) in rotation and re-measure every few months or after major body changes.

Should I size up in the cup or the band to fix side spillage?

Start with cup volume. If the band fits snugly, go up one cup. If the band is loose, go down a band and up a cup (e.g., 36C → 34D) to maintain cup volume with more support.

Can wire-free bras prevent side spillage?

Wire-free bras with supportive bands and full coverage can help, but ensure the band is firm. Look for multi-layered cup fabrics or inner slings for structure.