Bra Size Calculator

What is the Free Bra Size Calculator?

The free Bra Size Calculator converts your measurements into your correct bra size across US, UK, EU, AU, and FR sizing systems — all at once. Enter your band measurement (under the bust) and bust measurement (fullest part), choose inches or centimetres, and the tool calculates your size in every major international system. It also shows the cup volume per band size in a reference chart so you can compare fits.

• → Find your correct bra size from home measurements before shopping online
• → Convert your UK bra size to EU or US when buying from international retailers
• → Check if a bra from a different country (e.g. a French brand) will fit correctly
• → Re-measure after weight change, pregnancy, or breastfeeding to find a new size
• → Understand sister sizes — equivalent fits in neighbouring band/cup combinations

How to Use the Free Bra Size Calculator

1. 1 Choose your measurement unit — inches or cm.
2. 2 Measure your band size: wrap a soft measuring tape snugly around your ribcage, directly under your bust. Breathe out normally.
3. 3 Measure your bust size: wrap the tape loosely around the fullest part of your chest, keeping it parallel to the floor.
4. 4 Enter both measurements in the corresponding fields.
5. 5 The tool instantly shows your size in US, UK, EU, FR, and AU sizing systems. Use the Size Charts tab for a quick reference table.

Key Features

• 🌍
  5 sizing systems

  US, UK, EU (DE/IT/NL), FR (FR/BE/ES), and AU sizing — all calculated at once.
• 📏
  Inches & centimetres

  Switch between imperial and metric measurements with automatic conversion.
• 📊
  Cup reference chart

  See the cup difference table to understand how band size affects cup volume.
• 🔒
  Private

  Your measurements are never sent anywhere — all calculations happen in your browser.

Example Usage

Band measurement: 34 inches | Bust measurement: 38 inches

Cup difference: 4 inches → Cup: D

US / Canada: 34D
UK:          34D
EU (DE/IT):  75D
FR / BE:     90D
AU:          14D

Frequently Asked Questions about the Free Bra Size Calculator

What is the free Bra Size Calculator?

Find your bra size in US, UK, EU, AU, and FR sizing systems from your measurements.

Is the Bra Size Calculator free to use?

Yes, the Bra Size Calculator is completely free. No account, subscription, or signup is required — ever.

Does my data get uploaded anywhere?

No. The Bra Size Calculator runs entirely in your browser. Your data is never sent to any server.

Does it work offline?

Yes. Once the page has loaded, the tool works without an internet connection.

Which browsers are supported?

All modern browsers — Chrome, Firefox, Safari, and Edge. No plugins or extensions required.

How accurate are online bra size calculators?

Online calculators give a good starting estimate, but bra sizing varies by brand and style. Use the calculated size as a starting point, then try adjacent sizes — many women find they fit better in a sister size (same cup volume, different band/cup combination). For example, 34D and 36C hold the same cup volume.

What are sister sizes?

Sister sizes are bra sizes that share the same cup volume but have different band and cup letter combinations. If you go up one band size (e.g. 34 → 36), go down one cup letter (D → C) to maintain the same cup volume — and vice versa. This is useful when a style is not available in your exact size.

Why is my EU size 10 units higher than my US/UK band size?

EU band sizes (used in Germany, Italy, and the Netherlands) are calculated differently. The EU band number equals approximately 5× the band measurement in inches plus 15, meaning a US/UK 32 band corresponds to EU 70, a 34 to EU 75, and so on.

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