Side-by-Side Comparison
Clothing Sizes
Bra Sizes vs. Kids & Baby Clothing
Comparing 2 standards across 12 specifications. 12 key differences identified.
Comparing:
Bra Sizes
Kids & Baby Clothing
Bra sizing standardizes dual-dimensional breast support combining underbust Band Size (30 to 44) with Cup Volume (AA to H). Cup size is calculated directly from the difference between overbust fullest circumference and snug underbust ribcage measurement, cross-mapped across US, UK, EU, French (FR), and Italian (IT) systems.
Children's clothing sizes standardize growth stages from Preemie and Infant (0–24M) to Toddler (2T–5T) and Youth (Sizes 4–16), establishing height in centimeters/inches and weight in pounds/kilograms as primary fit metrics over calendar age.
Specification Comparison Table
12 Parameters| Parameter / Spec | ||
|---|---|---|
|
Governing Standards
|
ISO 3635 / EN 13402-4 / BS 6183 | ASTM D4910 (Baby) / ASTM D6554 (Toddler/Youth) / ISO 3635 |
|
Band Size Calculation
|
Snug underbust ribcage circumference (inches) rounded to nearest even number | — |
|
Cup Size Calculation
|
Fullest Overbust Measurement (in)–Band Size (in) = Cup Letter | — |
|
Cup Step Increment
|
1.0 inch (2.54 cm) difference per cup letter | — |
|
US Cup Scale
|
AA (<1"), A (1"), B (2"), C (3"), D (4"), DD/E (5"), DDD/F (6"), G (7"), H (8") | — |
|
Sister Sizing Rule
|
Cup volume stays equal if you go DOWN a band and UP a cup (e.g., 36B = 34C = 32D) | — |
|
International Band Baseline
|
US/UK 32 = EU 70 = FR 85 = IT 2 | US/UK 34 = EU 75 = FR 90 = IT 3 | — |
|
Baby / Infant Stage
|
— | Preemie, Newborn, 0-3M, 3-6M, 6-9M, 9-12M, 12-18M, 18-24M |
|
Toddler Stage (T)
|
— | 2T, 3T, 4T, 5T (engineered with extra room for diapers/training pants) |
|
Youth / Kids Stage
|
— | Sizes 4, 5, 6, 7, 8, 10, 12, 14, 16 (Alpha XS to XL) |
|
European System (EU)
|
— | Sized directly by child height in cm (e.g., EU 104 = 104 cm tall child / ~4 years) |
|
Primary Fitting Metric
|
— | Always use Height and Weight rather than age for optimal fit |