CalcMath.fun
Bra Size Calculator – Find Your Perfect Fit

Bra Size Calculator

Find your perfect fit across US, UK, EU, and other international sizing systems

This calculator estimates your bra size based on bust and band measurements. For accurate results, measure to the nearest ¼ inch or ½ cm. This calculator provides sizing for the United States, United Kingdom, European Union, France, Belgium, Spain, Australia, and New Zealand.

Size Calculator

Measure loosely around the fullest part of your bust.

Measure firmly under your bust, where the band sits.

How to Measure

Bra size measurement guide showing bust and band measurement locations
1
Bust Size: Measure around the fullest part of your bust while wearing a non-padded bra. Keep the measuring tape parallel to the ground and slightly loose for comfort.
2
Band Size: Measure directly under your bust, where the band sits. The tape should be snug but not tight – you should be able to fit two fingers underneath.
3
For Best Results: Stand straight with arms at your sides. Have someone help you if possible, or use a mirror to ensure the tape is positioned correctly.

Measurement Tips

  • Use a soft measuring tape, not a metal one
  • Wear a non-padded bra or no bra for the most accurate measurements
  • Round to the nearest ¼ inch or ½ centimeter
  • Measure twice to confirm your numbers

Bra Size Conversion Tables

Band Size Conversion

Band Size FR/BE/ES EU US/UK AU/NZ
XXS 75 60 28 6
XS 80 65 30 8
S 85 70 32 10
M 90 75 34 12
L 95 80 36 14
XL 100 85 38 16
XXL 105 90 40 18

Cup Size Chart (US/UK)

Bust/band difference (inches) US cup size UK/AU cup size
<1 AA AA
1 A A
2 B B
3 C C
4 D D
5 E or DD DD
6 F or DDD E
7 G or DDDD F
8 H FF
9 I G

Cup Size Chart (EU)

Bust/band difference (cm) Continental Europe cup size
10-11 AA
12-13 A
14-15 B
16-17 C
18-19 D
20-21 E
22-23 F
24-25 G

Finding Your Perfect Fit

Signs of Incorrect Bra Fit

Studies show that 70-85% of women wear incorrectly sized bras. Common signs include:

  • Band riding up in the back or digging into skin
  • Straps slipping off or digging into shoulders
  • Center panel not laying flat against the sternum
  • Cups wrinkling or causing breast tissue to spill over
  • Underwire sitting on breast tissue or not following the natural crease
  • Experiencing discomfort, pain, or restricted movement

Professional Fitting

While this calculator provides a good starting point, a professional bra fitting can help you find your ideal size and style. Many lingerie stores offer free fitting services.

This calculator is designed for informational purposes only. Individual body shapes and brand variations may affect your optimal size.