Understanding 34B Bra Size
A 34B bra size is considered a medium band size with a moderate cup size. This size is perfect for people with an average frame and moderate breast volume. Let's explore what makes this size unique and how to find the perfect fit.
Is 34B a Small or Medium Bra Size? Balanced Volume & Styling Tips
Fast facts about 34B
- Band 34 suits snug underbust measurements around 32–33 inches.
- B cups equal roughly a 2 inch difference between bust and band, providing modest-but-noticeable volume.
- On most medium frames it looks natural, while petite builds may see a fuller effect.
- Sister sizes 32C and 36A let you adjust band tension without sacrificing cup space.
How 34B is measured
Band fit
Aim for a 32–33 inch snug underbust so the band stays level yet comfortable.
Cup depth
Expect around 36 inches at the fullest point—two inches beyond the band measurement.
Support focus
Light foam or seamed cups keep shape defined; flexible wires preserve comfort for daily wear.
34B bust size in inches
| Measurement | Typical inches | How to capture it |
|---|---|---|
| Snug band (ribcage) | 32–33 in | Measure firmly under the bust and round to the 34 band label for bra tags. |
| Standing bust | 35.5–36.5 in | Keep the tape level at the fullest bust point; avoid squeezing tissue flat. |
| Approx. cup depth | 7.5–8.0 in | Measure from the wire base to nipple on a favourite bra to check how much cup height you need. |
| Band-to-bust difference | ≈2 in | Subtract the snug band from the standing bust to confirm the classic B-cup gap. |
34B bust size in centimeters
| Measurement | Typical cm | How to capture it |
|---|---|---|
| Snug band (ribcage) | 81–84 cm | Measure firmly under the bust, then translate to EU 75 / FR 90 / JP 75 band sizes. |
| Standing bust | 90–93 cm | Keep the tape level over the fullest point without compressing tissue. |
| Approx. cup depth | 19–20 cm | Measure from the underwire root to the apex on a favourite bra to ensure cup height matches. |
| Band-to-bust difference | ≈5 cm | Subtract the snug band from the bust to confirm the two-inch B cup gap in metric. |
- Leaning bust measurements around 37 in ensure there's enough tissue to fill the upper cup edge.
- If your bust sits nearer 35 in but cups still gap, try the 32C sister size for more depth.
- A loose tape or posture change can push you toward 34A or 34C, so remeasure when weight shifts.
- Metric reference: 34B typically aligns with 81–84 cm underbust and 90–93 cm bust measurements.
34B inch quick reference
- 34B ≈ 34 band label, 36 in bust, two-inch cup difference.
- Sister matches: 32C for a tighter band, 36A for a relaxed fit.
- International equivalents: EU 75B, FR 90B, UK 34B, JP 75B.
Different fabrics stretch differently—check band tension after a few wears and adjust if needed.
34B across popular sizing systems
Match US 34B to the most searched regional labels without leaving this guide.
Currently showing the United States (US) label — copy 34B to match tags instantly.
United States (US)
34B
United Kingdom (UK)
34B
Europe (EU)
75B
France (FR)
90B
Japan (JP)
80B
Australia (AU)
12B
Quick converter
Switch systems and copy the exact label for checkout forms or bra tags.
Need step-by-step help? Jump into the dedicated guides below for measurement nuances and shopping tips.
Perfect For
- Average frames
- Medium ribcages
- Moderate breast volume
- Balanced proportions
Recommended Styles
T-Shirt Bras
Perfect for everyday wear under fitted clothing
- Seamless
- Molded cups
- Comfortable
Balconette Bras
Great for creating a natural lift and shape
- Wide-set straps
- Lower cut cups
- Enhancing
Plunge Bras
Ideal for low-cut tops and dresses
- Deep V-neck
- Minimal coverage
- Versatile
How 34B tends to look
The size delivers a smooth, lightly rounded silhouette.
- T-shirt bras disappear under knits and work shirts.
- Unlined lace styles add texture while maintaining an understated profile.
- On athletic builds, subtle push-ups give evening outfits a touch more curve.
- Supportive sports bras with encapsulation minimise bounce during workouts.
34B compared with nearby sizes
Need a quick comparison before sister-sizing? Start here.
- 34A is one cup shallower—ideal if your cups wrinkle even with a snug band.
- 34C adds extra depth for fuller tissue or when push-up styles spill over.
- 36A keeps the B-cup volume but stretches the band for a looser ribcage fit.
Sister size playbook
- Move to 32C if the band creeps upward or feels loose by midday.
- Try 36A when you want additional breathing room around the ribcage.
- Size up to 34C if the neckline cuts in or you want extra cup coverage.
Fit checks before you buy
When trying on 34B bras, look for these key fit indicators:
- The band should fit snugly around your ribcage
- Cups should fully contain your breasts without spillage
- Straps should stay in place without digging in
- The center gore should lie flat against your chest
- Keep the band parallel to the floor on the middle hook for lasting support.
- Check the cup edge lies flat—molded or darted cups suit shallow roots.
- Adjust straps so they anchor the cup without digging; moderate tension prevents slipping.
- Look for side-support panels if tissue tends to shift toward the underarm.
Remember that fit can vary between brands and styles. Always try on bras before purchasing to ensure the perfect fit.
Common 34B questions
What size is 34B in other systems?
34B converts to 34B in UK sizes, 75B in EU, 90B in FR, 80B in JP, and 12B in AU.
Is 34B a small or medium size?
It straddles small-to-medium territory—larger than 34A, yet below the 36C/36D sizes many retailers cite as average.
What if 34B cups feel shallow?
Test the 34C or 32C sister sizes, or choose balconette and three-part cups for extra depth.
Which bra styles flatter 34B most?
Contoured T-shirt bras for daily wear, light push-ups for lift, and flexible wireless options for lounging all complement 34B.
What is the bust size for 34B in inches?
Record 32–33 inches snug under the bust (rounded to a 34 band) and about 35.5–36.5 inches at the fullest bust. The roughly two-inch gap indicates a B cup, but double-check posture and tape placement for accuracy.
Dial in your 34B fit
Double-check measurements, review the dedicated size guide, and compare visuals in the perception guide for outfit planning.