What Is 38B / 85B Bra Size? Bust Size and Measurements Explained

38B / 85B is a bra size with a larger band and a B cup. In many cm-based size charts, 38B is commonly close to 85B. A 38B has more cup volume than 34B or 36B because the same cup letter changes with band size.

What does 38B / 85B mean?

38B / 85B means the bra has a 38 band, commonly mapped close to 85 in many cm-based size charts, with a B cup.

The number refers to the band around the ribcage, while the letter B refers to the cup difference. A B cup usually means the bust is about 5 cm or 2 inches larger than the underbust.

Part of size	What it means	Simple explanation
38	Band size in inch-style sizing	Larger band than 34B or 36B
85	Common cm-based band label	Often used as the 38 band equivalent in SG/MY size charts
B	Cup letter	Usually about 5 cm or 2 inches bust-underbust difference

What are 38B bra measurements?

38B bra measurements usually mean an underbust around 83–87 cm, with the bust about 5 cm larger than the underbust.

This is a practical guide for 38B / 85B, but exact fit can vary by brand, fabric stretch, cup shape, and size conversion.

Size	Common SG/MY equivalent	Approx. underbust range	Bust-band difference	Fit notes
38B	85B	83–87 cm	About 5 cm / 2 in	Larger band with more B cup volume than 36B

What is 38B bust size?

38B bust size is usually estimated by adding about 5 cm to the underbust range, so the bust may sit around 88–92 cm in many size guides.

This is an approximate range, not a fixed body measurement. Two people can both wear 38B and still have different bust shape, breast spacing, and fit preferences.

Size	Approx. underbust	Approx. bust range	What to remember
38B / 85B	83–87 cm	88–92 cm	Bust range is approximate and brand fit may vary

Is 38B bigger than 36B?

Yes, 38B is bigger than 36B because it has a larger band and a larger cup volume.

The same cup letter does not mean the same cup volume across different band sizes. A 38B holds more volume than 36B, while 36B holds more volume than 34B.

Size	Common cm equivalent	Band comparison	Cup volume note
34B	75B	Smaller than 38B	Less cup volume than 38B
36B	80B	Smaller than 38B	Less cup volume than 38B
38B	85B	Larger band	More cup volume than 36B

What are the sister sizes of 38B?

The sister sizes of 38B are usually 36C and 40A because they have similar cup volume with different band sizes.

Sister sizing can help when the cup feels close to right, but the band feels too tight or too loose.

Current size	Sister size down	Sister size up	When to try it
38B / 85B	36C / 80C	40A / 90A	Try 36C if the band is loose; try 40A if the band feels tight

How should a 38B bra fit comfortably?

A 38B bra should feel secure around the band, smooth across the cups, and comfortable through normal movement without digging, rolling, or gaping.

The band sits level around your ribcage and does not ride up.
The cups sit smoothly without gaps or overflow.
The underband feels supportive but not tight or restrictive.
The straps stay in place without digging into the shoulders.
The bra feels comfortable when sitting, walking, and moving through the day.

Comfortable bra options for 38B / 85B

For 38B / 85B, soft support and a stable band can make everyday wear feel easier. Wireless, seamless, and comfort bra styles can help create a smooth fit without adding pressure.

Wireless Bra Collection

Good for gentle daily support without underwire pressure.

Wire-free comfort
Easy for long days
Best for relaxed everyday support

Seamless Bra Collection

Good for a smoother look under daily outfits.

Soft seamless finish
Smooth under fitted tops
Best for work and casual wear

Comfort Bra Collection

Good for easy coverage and practical support through the day.

Comfort-focused fit
Stable everyday feel
Best for longer wear

FAQ

Q1: Is 38B the same as 85B?
A: 38B is commonly close to 85B in many cm-based size charts, but sizing can vary by brand.

Q2: What is 38B bust size?
A: 38B bust size is often around 88–92 cm, based on an underbust around 83–87 cm plus a B cup difference of about 5 cm.

Q3: Is 38B bigger than 36B?
A: Yes, 38B is bigger than 36B because it has a larger band and a larger cup volume.

Q4: What is the sister size of 38B?
A: The sister sizes of 38B are usually 36C and 40A.

Q5: What bra is comfortable for 38B?
A: Wireless bras, seamless bras, and comfort bras often work well for 38B because they offer soft support, a smooth fit, and easier long-day comfort.