# item.guide
Side-by-Side Comparison Clothing Sizes

Bra Sizes vs. Women's Clothing

Comparing 2 standards across 13 specifications. 13 key differences identified.

Comparing:
Bra Sizes
Women's 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.

View full Bra Sizes spec sheet →

Women's international clothing sizing matrix cross-references standardized garment sizes across the United States (US 0–20), United Kingdom & Australia (UK 4–24), Continental Europe (EU 32–52), Italy (IT 36–56), and Japan (JP 3–23) with body measurements.

View full Women's Clothing spec sheet →

Specification Comparison Table

13 Parameters
Parameter / Spec
Governing Standards
ISO 3635 / EN 13402-4 / BS 6183 ASTM D5585 / EN 13402-3 / BS 3666 / JIS L 4005
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 —
Standard Sizing Range
— US 0 (XXS) to US 20 (3XL)
US to UK Offset
— UK Size = US Size + 4 (e.g., US 6 = UK 10)
US to EU Offset
— EU Size = US Size + 32 (e.g., US 6 = EU 38)
US to Italy Offset
— IT Size = US Size + 36 (e.g., US 6 = IT 42)
US to Japan Formula
— JP Size = (US Size × 2)–1 (e.g., US 6 = JP 11)
Petite vs Tall Inseams
— Petite (≤5'3" / 28" inseam) | Regular (5'4"–5'8" / 31") | Tall (≥5'9" / 34")