Ilusion · US / manufacturer Fit Guide image subset

Ilusion bra size calculator

Enter your measurements once and find the size you should actually try in the brands you shop. Compare US, UK and EU labels and see the nearby sizes.

  • Brand-aware sizing
  • US / UK / EU
  • No account required

How the Ilusion guide works

Use the Ilusion calculator

Looks up your underbust and bust measurements in the manufacturer’s published body-chart cells. Missing cells, gaps and overlapping matches are preserved rather than replaced with a guessed size.

Region and system
US / manufacturer Fit Guide image subset · US
Data reviewed
2026-10-07
Band labels covered
32, 34, 36, 38, 40, 42
Cup labels covered
A, B, C, D, DD

Bands are garment labels, not body ranges. Some combinations may be missing from this chart, and chart coverage is not a stock check.

Source scope and chart notes

Uses the official image’s nearest-whole-inch torso-under-bra/full-bust instructions and lookup matrix, not generic size subtraction. Worked example: torso 31, bust 36 → 34B. At band 38, the repeated DD entry at bust 44 is excluded; the torso-40/bust-43 cell prints “42” without a cup and is withheld. Blank cells are not filled.

Representative body-chart rows (in)
UnderbustBustLabel
29–30 in33–33 in32A
33–34 in37–37 in36A
35–36 in42–42 in38D
40–40 in44–44 in42B

These are a few sample rows. Ranges can overlap in the official chart, and the calculator keeps those overlaps.

Let’s find your starting point

Measure over a t-shirt or a lightly lined bra, or without one—whichever feels right.

Your results

Enter your measurements to see your starting size.

More detail
Your measurements

Use a soft tape measure, keeping it level and close to your body without pulling tight.

Step 1 of 2Around your ribcage, just beneath your bust.
Step 2 of 2Around the fullest part of your bust.

Bold brands are available for sizing. Gray brands are still being verified. Use arrow keys and Enter to choose.

125 matching brands.

Uses the official image’s nearest-whole-inch torso-under-bra/full-bust instructions and lookup matrix, not generic size subtraction. Worked example: torso 31, bust 36 → 34B. At band 38, the repeated DD entry at bust 44 is excluded; the torso-40/bust-43 cell prints “42” without a cup and is withheld. Blank cells are not filled. Data reviewed 2026-10-07.

Fit profile (optional)

For try-on tips only. It does not change your size or result, and it clears on reload or when you delete your measurements.

Issues you notice now
Your measurements are only used in this page. Nothing is sent or saved.
A note on fit

A number can guide you. Your comfort gets the final say.

Bra sizing isn’t consistent from one label—or even one style—to the next. Think of this as a useful first try, not a rule you have to fit.

Try the whole bra, not just the label

The band should feel secure without digging in; cups and straps should feel comfortable as you move.

Nearby sizes are worth a look

If your first try is close but not quite right, compare neighboring sizes and another style or cut.

Your body isn’t the problem

Brands use different patterns, fabrics, and size ranges. A mismatch says more about the garment than about you.