Spanx · United States / official help-centre Alpha Sizing

Spanx 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 Spanx guide works

Use the Spanx calculator

This page is a label conversion, not the manufacturer’s own measurement calculation. Your general starting size is translated into the brand’s published labels.

Translates your general starting size into this brand’s published chart labels. It does not calculate a size using the manufacturer’s own body-measurement method.

Region and system
United States / official help-centre Alpha Sizing · Spanx
Data reviewed
2026-10-07
Letter sizes covered
XS, XS/S, S, S/M, M, M/L, L/XL, L, XL/1X, XL, 1X, 1X/2X, 2X, 2X/3X

This chart returns letter sizes, not a numeric garment band. Blank combinations remain unavailable; coverage is not a stock check.

Source scope and chart notes

Only the official support guide’s “Alpha Sizing” image; slash labels (XS/S, XL/1X, etc.) and blank cells are preserved. No body method is enabled: the public blog describes a measured-band subtraction method while the linked support guide adds four/five inches first. Conflicting body methods must be resolved by the manufacturer, not blended. This converts a general starting label, not a fit prediction.

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.

Only the official support guide’s “Alpha Sizing” image; slash labels (XS/S, XL/1X, etc.) and blank cells are preserved. No body method is enabled: the public blog describes a measured-band subtraction method while the linked support guide adds four/five inches first. Conflicting body methods must be resolved by the manufacturer, not blended. This converts a general starting label, not a fit prediction. 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.