How to Measure Bra Size at Home
Learn how to use the How to Measure Bra Size Calculator, understand its assumptions and interpret the estimate.
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How to use this calculator
Open the How to Measure Bra Size Calculator and enter values using the units shown.
Formula and assumptions
The calculator uses the visible formula and the assumptions you enter. It does not silently retrieve private records or guarantee a real-world outcome.
Worked example
An underbust near 32 inches and a bust near 36 inches gives a starting estimate around band 32 with a four-inch cup difference.
Related calculators and guides
- Clothing Size Calculator
- Dress Size Calculator
- Body Shape Calculator
- How Clothing Size Conversions Work
Important limitations
Bra sizing is not standardized across brands or countries. Breast shape, tissue distribution, style and personal comfort can change the best-fitting size.
Disclaimer
Fit estimate only, not a medical assessment. Use the brand chart and try sister sizes when possible.
Frequently Asked Questions
- What does this calculator estimate?
- It estimates a starting band number and cup-difference index from two tape measurements. Brand sizing and fit can differ.
- Can I change the assumptions?
- Yes. Enter values that match your situation and review the displayed assumptions and limitations before using the result.
- Is the result guaranteed?
- No. The result is an estimate and should be independently verified before any medical, financial, travel, sizing, fitness, or purchasing decision.
Last updated 7/22/2026