How to Measure
1. Underbust Measurement
Wrap the tape measure snugly around your ribcage, directly under your bust. The tape should be level all around. Breathe normally and note the measurement.
2. Bust Measurement
Wrap the tape around the fullest part of your bust, typically at nipple level. Keep the tape level and don't pull too tight. Wear an unpadded bra for best results.
Enter Your Measurements
Your Bra Size
Recommended Size (US)
32D
Bust - Band = 4" difference
US Size
32D
UK Size
32D
EU Size
80D
Sister Sizes (Same Cup Volume)
Smaller Band
30DD/E
Your Size
32D
Larger Band
34C
Cup Size Reference
| Bust - Band Difference | US Cup | UK Cup |
|---|---|---|
| 0" | AA | AA |
| 1" | A | A |
| 2" | B | B |
| 3" | C | C |
| 4" | D | D |
| 5" | DD/E | DD |
| 6" | DDD/F | E |
| 7" | G | F |
| 8" | H | FF |
| 9" | I | G |
Signs of a Good Fit
Band
Snug and parallel to floor, fits 2 fingers underneath
Center Gore
Lies flat against your sternum
Cups
No spillage, gaps, or wrinkling
Straps
Stay in place without digging into shoulders
Quick Answer
Bra size = Band size + Cup size. Measure underbust (band) and fullest part of bust. Band size: round underbust to nearest even number. Cup size: bust minus band measurement determines cup (1"=A, 2"=B, 3"=C, 4"=D, 5"=DD/E). Example: 32" underbust + 36" bust = 4" difference = 32D.
Key Facts
- Band size = underbust measurement rounded to nearest even number
- Cup size = difference between bust and band measurement
- 1" difference = A, 2" = B, 3" = C, 4" = D, 5" = DD/E
- Sister sizes: same cup volume, different band (32D = 34C = 30DD)
- US and UK sizes differ after D cup (US DD = UK DD, US DDD = UK E)
- EU sizes use centimeters (US 34 = EU 75)
- Band should be snug on loosest hook
- 80% of support comes from the band, not straps
Frequently Asked Questions
How do I measure my bra size correctly?
Use a soft measuring tape. For underbust: measure snugly around your ribcage, directly under your bust. For bust: measure around the fullest part of your bust while wearing an unpadded bra. Keep the tape level and not too tight.
What are sister sizes?
Sister sizes have the same cup volume but different band sizes. Going up a band size means going down a cup size, and vice versa. For example, 34C has the same cup volume as 32D and 36B. Use sister sizes to fine-tune your fit.
Why does my calculated size differ from what I usually wear?
Bra sizing varies between brands and styles. Many people wear the wrong size due to inconsistent sizing standards. The calculated size is a starting point - try it on and adjust based on fit. The band should be snug but not tight, and cups should fully contain breast tissue.
What is the difference between US, UK, and EU sizing?
US and UK use inch-based bands (32, 34, 36...) but differ in cup progression after D. UK adds double letters (DD, E, F, FF, G, GG...). EU uses centimeter bands (70, 75, 80...) and simpler cup letters. Always check the specific brand's size chart.
How should a properly fitting bra feel?
The band should be snug and parallel to the floor, able to fit two fingers underneath. The center gore should lie flat against your sternum. Cups should fully contain breast tissue without spillage or gaps. Straps should stay in place without digging in.