Understanding 30A Bra Size
A 30A bra size is considered a small band size with a small cup size. This size is perfect for people with a petite frame and smaller breast volume. Let's explore what makes this size unique and how to find the perfect fit.
Is 30A considered big or small?
Fast facts about 30A
- Snug 30 band with a 1-inch cup jump.
- Standing bust around 30.5–31.5 in keeps the cup filled.
- Share cup volume with 28B for band tweaks.
- Always scoop-and-swoop and check the gore for a flat anchor.
How 30A is measured
Band fit
Aim for a snug 28.5–29.5 in underbust so the 30 band stays level without digging.
Cup depth
Standing bust in the 30.5–31.5 in range keeps roughly a 1-inch cup difference.
Support focus
Choose firm wings, fully adjustable straps, and swap sister sizes if the band shifts during wear.
30A bust size in inches
| 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 band label. |
| Standing bust | 30.5–31.5 in | Keep the tape level across the fullest point while standing tall. |
| Band-to-bust difference | ≈1 in | Subtract your snug band from the standing bust to confirm cup depth. |
| Approx. cup depth | 2.5–3.5 in | Measure from the underwire root to the apex on a well-fitting bra. |
30A bust size in centimeters
| Measurement | Typical cm | How to capture it |
|---|---|---|
| Snug band (ribcage) | 72.4–74.9 cm | Measure firmly beneath the bust, then map it to EU/FR/JP band labels. |
| Standing bust | 77.5–80 cm | Keep the tape level across the fullest point without compressing tissue. |
| Band-to-bust difference | ≈2.5 cm | Use the difference to double-check your metric cup depth. |
| Approx. cup depth | 6.4–8.9 cm | Trace from underbust to apex on a supportive bra to check projection. |
- Sits below the most common band range of 32-36, so the cups rest on a petite frame.
- Often reads as modest even on fuller frames because the cup depth is shallow.
- Monitor posture and band tension—small shifts change how the size looks.
- Try sister sizes 28B to fine-tune band tension.
Quick reference for 30A
- 30A ≈ band 30 label with a 1-inch cup step.
- Projected bust lands around 30.5–31.5 in.
- Use the calculator to convert this size across US/UK/EU/JP systems.
Ranges are approximations—double-check your own measurements for precision.
30A across popular sizing systems
Match US 30A to the most searched regional labels without leaving this guide.
Currently showing the United States (US) label — copy 30A to match tags instantly.
United States (US)
30A
United Kingdom (UK)
30A
Europe (EU)
65A
France (FR)
80A
Japan (JP)
70A
Australia (AU)
8A
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
- Petite frames
- Smaller ribcages
- Smaller breast volume
- Minimal coverage needs
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 30A tends to look
30A pairs a 30-band with a 1-inch cup jump, so the silhouette changes with your frame and bra style.
- Keep 28B in mind—they share cup volume while tweaking the band.
- Shape, strap placement, and fabric choice all influence whether the size looks subtle or bold.
30A compared with nearby sizes
Quick reference when you’re deciding whether to change the band, the cup, or both.
- 30B adds depth while keeping the band snug if you spill out of 30A.
- 28B keep the same cup volume but tweak band tightness for comfort.
Sister size playbook
- Try 28B when you need tighter or looser band support.
Fit checks before you buy
When trying on 30A 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.
- Scoop and swoop tissue into the cups before checking the gore.
- Adjust straps for lift, then reassess comfort after an hour of wear.
Remember that fit can vary between brands and styles. Always try on bras before purchasing to ensure the perfect fit.
Common 30A questions
What size is 30A in other systems?
30A converts to 30A in UK sizes, 65A in EU, 80A in FR, 70A in JP, and 8A in AU.
What does 30A mean?
30A pairs a 30 band with a cup that is roughly 1 inches deeper than the band measurement.
Which sister sizes match 30A?
30A shares cup volume with 28B. Use them to tighten or relax the band.
How can I confirm this is my best fit?
Measure snug and standing bust, check for smooth cup edges, and ensure the band stays level after a few minutes of wear.
Check 30A with our tools
Measure with the calculator, compare sister sizes, and review the perception guide for styling tips.