What is 38B Bra Size? 38B Measurements in Inches & cm, Sister Sizes and Fit

A 38B bra size means a 38 band (your underbust measures about 33 to 34 inches) and a B cup (your bust measures about 40 inches, 2 inches more than the band). In centimetres that is an underbust of 84 to 86 cm and a bust of about 102 cm. 38B is the most common 38 size and the sister size of 36C. Lovable India sells 38B in every style from non-padded cotton to t-shirt, padded and sports bras: see all 38B bras.

38B bra size measurements

Measurement	Inches	Centimetres
Underbust (band 38)	33–34	84–86
Bust (cup B)	40	102
Bust minus band	2	5

The band number is not your bust; it is your underbust plus 4 (even) or 5 (odd) inches, which is how Indian and international brands size bras. The cup letter is the difference between bust and band: A is 1 inch, B is 2, C is 3, D is 4, E is 5.

How to check if you are a 38B

Wrap a soft tape snugly under your bust and note the inches. 33 or 34 inches points to band 38.
Wrap the tape loosely around the fullest part of your bust. About 40 inches with a 38 band points to a B cup.
Try the bra: the band should sit level across your back on the loosest hook, the centre panel should touch your breastbone, and the cup should be full with no gap and no spill.

If the numbers do not match this exactly, use the full bra size chart or the bra size calculator.

38B sister sizes

Sister sizes hold the same cup volume on a different band. If a 38B band feels tight, try 40A; if it rides up and feels loose, try 36C. The cup letter changes but the cup itself stays the same size.

If 38B…	Try	Why
band is loose, cup fits	36C	tighter band, same cup volume
band is tight, cup fits	40A	looser band, same cup volume
cup spills over	38C	same band, one cup larger
cup gaps or wrinkles	38A	same band, one cup smaller

38B compared with nearby sizes

38B vs 38A: same band; 38B has a cup one inch larger (bust 40 vs 39 inches).
38B vs 38C: same band; 38C has a cup one inch larger (bust 41 inches).
38B vs 40B: same cup letter, but 40B has a 2-inch longer band and a slightly larger cup, because cup volume grows with band size. 40A is the true equivalent of 38B, not 40B.
38B vs 36B: same cup letter on a 2-inch shorter band; the 36B cup is slightly smaller.

Best bra styles for 38B

B cups suit almost every style. Lightly padded and push-up bras add shape under fitted tops; t-shirt and seamless bras disappear under thin fabrics; non-padded cotton bras are the coolest daily option; non-wired works fine because the cup is light. Browse by style: t-shirt bras, padded bras, non-padded bras, seamless bras, sports bras and full coverage bras, then filter to 38B.

38B bra FAQs

Is 38B a small, medium or large bra size?

38B is a medium-to-plus size: a wider ribcage with a modest cup, the same cup volume as 36C. The cup letter alone does not tell you the volume: a B cup on a 38 band is a different size from a B cup on a 42 band.

What is 38B bra size in cm?

Underbust 84 to 86 cm and bust about 102 cm. European sizing calls this 85B.

What is the difference between 38B and 40B?

The band. 40B is for an underbust of 35 to 36 inches, 38B for 33 to 34 inches. Because cup volume scales with the band, the 40B cup is also a little larger than the 38B cup.

My 38B band rides up at the back. What should I do?

The band is too loose. Try 36C (tighter band, same cup) or tighten to the inner hook. A band that rides up gives no support no matter how the straps are set.

Which 38B bra is best for daily use?

A non-padded or lightly padded, non-wired, full-coverage cotton bra. See 38B bras on Lovable India from ₹179.

Does 38B change after weight gain or loss?

Usually by one band size for every 5 to 7 kg, and sometimes a cup. Re-measure every six months and after any change in weight, pregnancy or exercise.

More bra size guides

Bra Size Chart | Bra Size Calculator | What A, B, C, D Cup Sizes Mean

By band: 30 Bra Size | 32 Bra Size | 34 Bra Size | 36 Bra Size | 38 Bra Size

By size: 30B | 32B | 32C | 32D | 34B | 34C | 34D | 36B | 36C | 36D | 38C | 38D

By cup: A Cup | B Cup | C Cup | D Cup

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