Bra Size Calculator: Find Your Perfect Fit in Seconds

Finding the right bra size can be surprisingly difficult. Ill-fitting bras cause discomfort, back pain, and poor support. Our free Bra Size Calculator makes it easy. Just enter your bust and underbust measurements, and get accurate results for US, UK, EU, French, Australian, and New Zealand sizing systems.

How Our Bra Size Calculator Works

We use industry-standard methods to calculate your size:

Inputs:

• Bust circumference (fullest part of the chest)
• Underbust circumference (firm measurement directly under the breasts)
• Support for both inches and centimeters

What You’ll Get:

• Band size and cup size in multiple systems
• International size conversions
• Clear explanations for each result

Supported Sizing Systems

• US / UK – Most common in North America and Britain
• EU (EN 13402) – European standard
• FR / BE / ES – French, Belgian, and Spanish sizing
• AU / NZ – Australian and New Zealand dress sizing

Why Bra Size Matters

A correctly fitted bra:

• Improves posture and reduces back/shoulder pain
• Provides better support during exercise
• Enhances appearance and confidence
• Prevents skin irritation and discomfort

Many women wear the wrong size — our calculator helps you find your true fit.

How to Measure Correctly

For Best Results:

• Measure your underbust firmly (exhale, snug but not tight)
• Measure your bust at the fullest part (usually across the nipples), keeping the tape level
• Enter both measurements in the calculator

Tip: Measure wearing a non-padded bra or no bra for highest accuracy.

Example Calculation

Measurements:
Bust = 37 inches | Underbust = 34 inches

Results:

• US / UK: 34C
• EU: 75C
• FR / BE / ES: 90C
• AU / NZ: 12C

Pro Tips for Bra Shopping

• Always try bras on before buying — sizes vary between brands
• Check the band — it should feel snug on the loosest hook
• The cups should be smooth without spillage or gaps
• Re-measure every 6–12 months or after major weight changes