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Bra Measurement Chart About

Bra Measurement Chart – Complete Sizing Reference

Find your perfect fit with our comprehensive bra size charts. Compare US, UK, EU, AU, and FR sizing – plus band conversion, cup comparison, and sister size guide.

Band Size Conversion Chart

Band sizes vary by region. Use this chart to convert your band size across US, UK, EU, AU, and FR systems.

Underbust (in) Underbust (cm) US / UK EU AU / NZ FR / ES
26.5 – 28.567 – 722860675
28.5 – 30.572 – 773065880
30.5 – 32.577 – 8232701085
32.5 – 34.582 – 8734751290
34.5 – 36.587 – 9236801495
36.5 – 38.592 – 97388516100
38.5 – 40.597 – 102409018105
40.5 – 42.5102 – 107429520110
42.5 – 44.5107 – 1124410022115
44.5 – 46.5112 – 1174610524120
46.5 – 48.5117 – 1224811026125
48.5 – 50.5122 – 1275011528130
50.5 – 52.5127 – 1325212030135
52.5 – 54.5132 – 1375412532140
54.5 – 56.5137 – 1425613034145

* EU bands are measured in centimetres. FR bands are typically EU band + 15.

Cup Size Conversion Chart

Cup letters vary by region, especially from DD upward. Use this chart to convert your cup size across systems.

Diff (in) Diff (cm) US UK EU AU / NZ FR
0 – ½0 – 1.3AAAAAAAAAA
12.5AAAAA
25.0BBBBB
37.6CCCCC
410.0DDDDD
512.7DD / EDDEDDE
615.2DDD / FEFEF
717.8GFGFG
820.3HFFHFFH
922.9IGIGI
1025.4JGGJGGJ
1127.9KHKHK
1230.5LHHLHHL
1333.0MJMJM
1435.6NJJNJJN

* US and UK cups match up to D. From DD upward, they diverge.

Complete Bra Size Chart (US)

Find your band in the left column and your cup in the top row. The intersection shows your complete US bra size.

Cup / Band 2830323436 3840424446
AA28AA30AA32AA34AA36AA38AA40AA42AA44AA46AA
A28A30A32A34A36A38A40A42A44A46A
B28B30B32B34B36B38B40B42B44B46B
C28C30C32C34C36C38C40C42C44C46C
D28D30D32D34D36D38D40D42D44D46D
DD / E28DD30DD32DD34DD36DD38DD40DD42DD44DD46DD
DDD / F28DDD30DDD32DDD34DDD36DDD38DDD40DDD42DDD44DDD46DDD
G28G30G32G34G36G38G40G42G44G46G
H28H30H32H34H36H38H40H42H44H46H

* Chart shows US sizing. UK cups differ from DD upward – see cup conversion chart above.

Sister Size Chart

Sister sizes have the same cup volume but different band and cup letter combinations. If your size is unavailable, try a sister size.

Your Size Sister (Tighter Band) Sister (Looser Band)
28A—30AA
28B—30A
28C—30B
28D—30C
30A28B32AA
30B28C32A
30C28D32B
30D28DD32C
32A30B34AA
32B30C34A
32C30D34B
32D30DD34C
32DD30DDD34D
34A32B36AA
34B32C36A
34C32D36B
34D32DD36C
34DD32DDD36D
36A34B38AA
36B34C38A
36C34D38B
36D34DD38C
36DD34DDD38D
38A36B40AA
38B36C40A
38C36D40B
38D36DD40C
38DD36DDD40D
40A38B42AA
40B38C42A
40C38D42B
40D38DD42C
42A40B44AA
42B40C44A
42C40D44B
42D40DD44C
44A42B46AA
44B42C46A
44C42D46B
44D42DD46C
46A44B48AA
46B44C48A
46C44D48B
46D44DD48C

* Sister size rule: Band – 2 = Cup + 1 (tighter band). Band + 2 = Cup – 1 (looser band).

How to Measure Your Bra Size

Follow these simple steps to get accurate measurements for the charts above.

📏 1. Measure Your Underbust (Band)

Wrap a soft tape measure snugly around your ribcage, directly under your bust. Keep the tape level and parallel to the floor. Take the measurement after exhaling normally.

Tip: Round to the nearest even number – e.g., 31" → 32 band.

📐 2. Measure Your Bust (Cup)

Measure around the fullest part of your bust – usually across the nipples. Keep the tape level and don't pull it tight. The tape should sit gently against your skin.

Tip: Take two or three measurements and average them for accuracy.

💡 Formula: Cup Size = Bust Measurement – Band Measurement
1" difference = A cup · 2" = B · 3" = C · 4" = D · 5" = DD · 6" = DDD · 7" = G · and so on.

Quick Reference – Common Conversions

Use this quick reference to convert your size across systems.

USUKEUFRAU / NZ
30A30A65A80A8A
30B30B65B80B8B
30C30C65C80C8C
30D30D65D80D8D
32A32A70A85A10A
32B32B70B85B10B
32C32C70C85C10C
32D32D70D85D10D
34A34A75A90A12A
34B34B75B90B12B
34C34C75C90C12C
34D34D75D90D12D
34DD34DD75E90E12DD
34DDD34E75F90F12E
34G34F75G90G12F
36A36A80A95A14A
36B36B80B95B14B
36C36C80C95C14C
36D36D80D95D14D
36DD36DD80E95E14DD
36DDD36E80F95F14E
36G36F80G95G14F

* Quick reference only. Use the full charts above for complete conversions.

Frequently Asked Questions

What is the difference between US and UK bra sizes?

US and UK bands use the same inch numbers (e.g., 34 is 34 in both). However, cup letters differ from DD upward. US DDD = UK E, US G = UK F, US H = UK FF.

How do I convert EU band size to US?

EU bands are measured in centimetres. Subtract 4 from the US band and multiply by 2.54 to get the EU band. For example, US 34 → (34-4) × 2.54 = 76 cm → EU 75.

What are sister sizes?

Sister sizes have the same cup volume but different band and cup letter combinations. If you go down one band size, go up one cup size. If you go up one band size, go down one cup size. For example, 34C → 32D (tighter band) or 36B (looser band).

How is cup size calculated?

Cup size is the difference between your bust measurement and your band measurement. Each inch of difference equals one cup letter: 1" = A, 2" = B, 3" = C, 4" = D, 5" = DD, 6" = DDD, 7" = G, and so on.

Why is my size different in different brands?

Different brands use different fit models, fabric, and construction. Your size may vary by brand – that's why sister sizing and trying on multiple sizes is recommended.

Does IMRango store my measurements?

No. Everything runs locally in your browser. We do not collect, store, or share any of your personal data or measurements.

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Last Updated: August 2026