Is 30G a Big or Small Bra Size? Narrow Band, Deep Cup Guide
30G marries a narrow band with a deep cup, delivering dramatic projection on a petite frame while keeping the band compact. This breakdown shows exactly what a 30G bra looks like, how it converts, and how to keep it supported.
Fast facts about 30G
- Band 30 supports snug underbust measurements around 28–29 inches.
- G cups signal roughly a 7 inch difference between bust and band, so volume is concentrated and lifted.
- Front-on it can look balanced thanks to the slim ribcage; from the side projection is pronounced.
- Sister sizes 28H and 32F maintain cup volume while adjusting band tension.
- This guide shows what a 30G bra looks like, how it compares to 30FF/32F, and the conversions to every major system.
How 30G is measured
Band fit
Aim for a 28.5–29.5 inch snug underbust so the 30 band grips firmly without digging.
Cup depth
Expect around 36–37 inches at the fullest point—roughly seven inches beyond the snug band.
Support focus
Look for narrow wires, multi-part cups, and 3–4 hook closures to stabilise the extra projection.
30G bust size in inches
Use these inch checkpoints to confirm your measurements sit squarely in 30G before ordering globally.
| Measurement | Typical inches | How to capture it |
|---|---|---|
| Snug band (ribcage) | 28.5–29.5 in | Measure firmly under the bust on an exhale, then round to the 30 band label. |
| Standing bust | 35.5–37.0 in | Keep the tape level across the fullest point while you stand tall and relax your shoulders. |
| Band-to-bust difference | ≈7 in | Subtract your snug band from the standing bust to verify the classic G-cup gap. |
| Approx. cup depth | 10.0–10.5 in | Measure from the underwire to the apex on a well-fitting bra—confirms the depth needed for full projection. |
30G bust size in centimeters
| Measurement | Typical cm | How to capture it |
|---|---|---|
| Snug band (ribcage) | 72–75 cm | Measure firmly under the bust, let the tape rebound slightly, then match to EU/JP band 65 (US/UK 30). |
| Standing bust | 90–94 cm | Keep the tape level across the fullest point while standing naturally; avoid compressing tissue. |
| Band-to-bust difference | ≈18 cm | Subtract the snug band from the standing bust to confirm the G-cup depth in metric sizing. |
| Approx. cup depth | 25–27 cm | Run the tape from underwire root to apex on a supportive bra to ensure the cup height matches your projection. |
- Leaning bust readings around 37.5–38 in show there is enough tissue to fill the upper cup.
- If your bust measures closer to 35.5 in but the band feels loose, try the 28H sister size for a tighter anchor.
- Hormonal swelling can nudge you toward 30FF/30GG—recheck measurements during cycle peaks.
- Need the metric view? 30G typically lands around 72–75 cm underbust and 90–94 cm bust—use it for EU/JP conversions.
30G inch quick reference
- 30G ≈ 30 band label, 36–37 in bust, seven-inch cup difference.
- Sister matches: 28H for more hold, 32F for a touch of breathing room.
- International equivalents: EU 65I, FR 80I, UK 30G, JP 65I.
Because the cup is deep, prioritize narrow wires and firm wings to keep projection centred.
How 30G tends to look
Wondering what a 30G bra looks like? Expect a lifted, projected profile from the side, while the petite band keeps the front silhouette streamlined.
- Under fitted tees it creates a lifted, rounded apex with visible waist definition.
- On shorter torsos it can appear dramatic; taller frames distribute the volume more evenly—dropping to 30FF trims projection if you want a subtler outline.
- Plunge and balconette styles highlight the waist-to-bust contrast without flattening the cup.
- High-impact sports bras with encapsulation plus compression help manage momentum.
30G compared with nearby sizes
Use these quick comparisons to translate 30G into its equivalent sizes and neighbouring cups.
- 30G vs 30FF: the 30FF cup is roughly half an inch shallower, so it suits slightly less projection.
- 30G vs 32F: 32F keeps the cup depth but relaxes the band by one step—ideal if you need breathing room.
- 30G equivalent size: EU 65I / FR 80I / JP 65I. Drop to 28H or up to 32F when you need to tweak the band.
Sister size playbook
- Shift to 28H when you need a firmer anchor and narrower wire tracing the root.
- Move to 32F if the band feels restrictive or you’re between hook settings.
- Try 30FF when you just need a touch less depth or want extra cup containment.
Fit checks before you buy
- Confirm the gore lies flat—if it floats, explore deeper plunge or larger cup options.
- Choose bras with closer-set straps to stop them sliding off narrow shoulders.
- Look for 3–4 hook closures or reinforced wings to distribute weight along the back.
- Favour side support panels or stretch lace uppers to keep tissue centred and contained.
Common 30G questions
What does a 30G bra look like on the body?
It combines a slim 30 band with a deep, projected cup. From the front it frames the waist; from the side it shows a rounded, lifted silhouette anchored by narrow wires and firm wings.
What is the 30G equivalent size?
The closest sisters are 28H for a tighter band and 32F for more ease. In metric systems 30G maps to EU 65I, FR 80I, and JP 65I—swap letters, not cup volume.
How does 30G compare to 30FF?
30FF is one cup shallower. If you spill or feel compressed in 30FF, 30G adds about half an inch of depth while keeping the petite band.
Where can I find supportive 30G bras?
Shop UK/full-bust brands, online fit boutiques, or multi-size retailers that stock 28–32 bands. Filter for narrow wires, side support panels, and 3–4 hook closures to tame projection.
Keep 30G supported
Verify your measurements with the calculator, explore the 30G size guide, and compare silhouettes in the perception gallery for outfit planning.