Dr. Emily Carter
LinkedInDr. Emily Carter Dr. Emily Carter is a renowned expert in lingerie design, with over 20 years in fashion and functional apparel. Her expertise in fabric and fit drives Tarbo’s mission to create comfortable, seamless lingerie that empowers every woman to feel confident and at ease, no matter the occasion.
Finding the perfect bra can instantly transform your daily experience—from feeling confident and fully supported to never worrying about spillage or gaping cups again. If you've ever wondered what those letters really mean, or how A through G cups actually differ in fit, appearance, and support needs, this guide is made for you. We'll break down cup sizes in a clear, easy-to-understand way to help you shop smarter and feel your most comfortable, confident self!
Cup size isn't just a random letter—it's the volume difference calculated from your underbust (band size) and overbust measurements. Ready to ditch the guesswork? Let's dive in!
Understanding Bra Cup Sizes
A bra size consists of a number (band size, usually in cm like 70, 75, 80) + a letter (cup size). The cup letter represents the difference between your overbust (fullest part of the bust) and underbust (ribcage just below the breasts). Common standards (China/EU/Japan systems) are:
● A cup: approx. 10 cm difference
● B cup: approx. 12.5 cm difference
● C cup: approx. 15 cm difference
● D cup: approx. 17.5 cm difference
● E cup: approx. 20 cm difference
● F cup: approx. 22.5 cm difference
● G cup: approx. 25 cm difference
(Note: Sizing varies slightly by brand/country—US uses inches, where 1 inch ≈ 2.54 cm; UK often labels DD as E, DDD as F, etc. Tarbo primarily uses Alpha sizing: S/M/L/XL/2XL/3XL, which covers medium cup ranges, with wide-band and jelly-lift designs accommodating larger volumes. Check details in our Tarbo.)
Pro tip: Studies show about 80% of women wear the wrong size! Measure yourself and refer to Tarbo's sizing chart for accuracy.
How to Measure Your Cup Size Correctly
Grab a soft measuring tape:
1. Underbust: Measure snugly (but not tight) around your ribcage just below the breasts.
2. Overbust: Measure loosely around the fullest part of your breasts (don't compress). Overbust minus underbust = difference → corresponds to your cup letter.
If you're between sizes or unsure, try "sister sizes" (same cup volume, different band) for a better fit. Tarbo tip: The center gore should sit flat against your chest, breasts fully enclosed with no spillage or gaps, and the band level (not riding up).
A Cup vs B Cup Comparison
A cups are smaller, with about a 10 cm difference. They have minimal projection and light volume, creating a natural, slim silhouette. Perfect for petite frames or anyone wanting a subtle, barely-there look—almost invisible under fitted tops, super lightweight and comfy.
B cups step up with about a 12.5 cm difference, adding a bit more fullness and natural curve. Rounded and moderate, this is a very common size for many Asian women—gentle curves without being overpowering, versatile for everyday outfits.
Tarbo Recommendations for A & B Cups (lightweight wireless, seamless designs—S/M sizes ideal)
● Tarbo Everyday Wireless Bralette — Lightweight, trace-free, all-day comfort.
● Tarbo Seamless Skin-like Bra — Smooth, no-show, natural lift.
B Cup vs C Cup Comparison
B cups transition smoothly into C cups (about 15 cm difference). C cups are often viewed as "medium-full." Noticeable yet balanced volume, naturally full and uplifted shape that fills out tops beautifully and enhances feminine curves. C cups strike an excellent balance of comfort, support, and aesthetics—suitable for most body types.
Tarbo Recommendations for B & C Cups (gentle lift, versatile full coverage—M/L sizes fit well)
● Tarbo Light-Lift Shaping Wireless Bra — Soft uplift, pressure-free all day. Jump link: Tarbo® V Neck Mesh Seamless Full Coverage Bralette | Tarbo (V-neck mesh seamless full coverage, ideal B-C balance with light support)
● Tarbo V-Neck Camisole Bra — Soft fabric, perfect for layering. Jump link: Tarbo® Seamless V Neck Jelly Bralette Wide Band Lace Support | Tarbo (wide-band lace V-neck jelly support, everyday B-C favorite)
C Cup vs D Cup Comparison
C cups lead into D cups (about 17.5 cm difference). D cups bring more pronounced fullness and forward projection. Curves stand out more—great for accentuating your figure. They need solid support to prevent bounce or strap slippage; D cups create stunning deep-V looks, amazing in low-neck or wrap dresses.
Tarbo Recommendations for C & D Cups (anti-spill, strong full-coverage support—L/XL sizes cover well)
● Tarbo Smooth No-Show Wireless Bra — Anti-spill design, sleek lines.
● Tarbo Racerback Sports Bra — Ideal for active days, ample containment. Jump link: Tarbo® Seamless Jelly Strip Sports Bralette with Criss Cross back | Tarbo (criss-cross jelly sports style, stable C-D activity support)
Larger Cup Comparisons: E, F, and G Cups
For fuller busts, cup sizes continue upward. These require more engineered support (wider sides, stronger straps, full cups) to evenly distribute weight and reduce back/shoulder strain. Tarbo's jelly series with wide bands supports up to 3XL, accommodating E+ volumes.
E Cup (often called DD in some systems, approx. 20 cm difference)
E cups have significant volume—noticeably fuller and more projected than D. They create a strong, voluptuous presence from front and side views, often needing full-coverage or minimizer styles to contain everything. E cups showcase bold, empowering curves—sexy and comfortable when properly fitted.
Tarbo Recommendation for E Cups
● Tarbo Full-Coverage Support Bra — Powerful lift, no digging. Jump link: Tarbo® Jelly Bra with Wire-Free Lift and Seamless Full Coverage Design | Tarbo (full-coverage jelly lift, stable for E volumes)
F Cup (approx. 22.5 cm difference)
F cups enter "high projection" territory—deep and side-full. The bust looks commanding from the front, often requiring extended side panels or high sides for complete containment and no side spillage. F cups sculpt dramatic curves, but mainstream options are limited—prioritize wide bands and adjustable straps.
Tarbo Recommendation for F Cups
● Tarbo High-Support Longline Bra — All-day stability, no shifting.
G Cup (approx. 25 cm difference)
G cups represent very high volume and commanding presence—extreme projection that demands specialized bras (often molded cups, reinforced underwires, or longline styles in other brands). G cups create a striking, curvaceous silhouette, but poor support can cause shoulder/back strain. The right bra turns G cups into your biggest confidence asset!
Tarbo Recommendation for G Cups
● Tarbo Ultimate Support Bra — Maximum lift and smoothing. Jump link: Tarbo® Womens Seamless Wireless Push Up Bra Wide Band Support | Tarbo (wide-band seamless wireless push-up, supports C-F+ and higher volumes)
No matter if you're an A cup or a G cup, the right bra should feel like a "second skin"—comfortable yet reliable. Explore Tarbo's full range of wireless, shaping, and plus-size options designed for real bodies!
Common Questions
How different are E/F/G cups from D, and does Tarbo support them?
Yes—more projection & fullness each step up. Tarbo wide-band jelly styles (up to 3XL) work for E–G; best options: Wide Band Padded Wireless Push Up Bra or Full Coverage Jelly Bra.
How do I tell if I’m A/B or C/D, and which Tarbo bra to start with?
Measure difference: 10–12.5 cm → A/B (try Seamless Jelly Lift Plunge V Bra); 15–17.5 cm → C/D (try Jelly Bra Full Coverage). Check Alpha sizes in Tarbo Size Guide.
What does the cup letter (A–G) mean?
It’s the difference between overbust and underbust: A ≈10 cm, B ≈12.5 cm, C ≈15 cm, D ≈17.5 cm, E ≈20 cm, F ≈22.5 cm, G ≈25 cm. Bigger letter = more volume/projection.
