Bra Size Calculator - Find Your Size with Chart
Find your correct bra size at home. Enter your measurements for an accurate fit without a fitting room.
Tool Interface
Your measurements
Bra size chart
Find your band row (by underbust inches), then read across to your cup column. Bust = band + cup difference.
| Band | Underbust | AA | A | B | C | D | DD/E | F | FF | G | GG | H | HH | J | JJ | K |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 30 | 29-31 in | 30.5 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 |
| 32 | 31-33 in | 32.5 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |
| 34 | 33-35 in | 34.5 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 |
| 36 | 35-37 in | 36.5 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 |
| 38 | 37-39 in | 38.5 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 |
| 40 | 39-41 in | 40.5 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 |
| 42 | 41-43 in | 42.5 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 |
| 44 | 43-45 in | 44.5 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 |
Rate this tool
About This Tool
Find Your Bra Size in Seconds
The Bra Size Calculator estimates your US bra size from two simple measurements. Enter your underbust and bust, and the tool calculates your band and cup size plus sister sizes that hold the same cup volume with a different band fit.
It is useful when shopping online, checking whether your current size still fits, or learning how sister sizing works before trying new brands. The calculator supports both inches and centimeters. It is free and needs no signup.
How to Use the Bra Size Calculator
Four steps to your estimated size.
- Choose your units: Select inches or centimeters for your measurements.
- Measure your underbust: Wrap the tape snugly around your ribcage just under the bust. Keep it level, breathe out normally and note the number.
- Measure your bust: Measure around the fullest part of your bust while wearing an unpadded bra. Keep the tape level but not tight.
- Click Calculate Bra Size: The tool shows your estimated US band and cup size together with sister sizes to try.
Measuring Tips for Best Accuracy
- Use a soft tape: A flexible measuring tape follows your body. A rigid ruler will not work.
- Stay level: The tape should sit horizontal all the way around, front and back.
- Do not pull tight on the bust: The bust measurement should rest gently on the fullest point.
- Re-measure yearly: Bodies change, so check your numbers before ordering from a new brand.
Key Features
- US sizing: Results use standard US band and cup sizes.
- Inches and centimeters: Enter measurements in whichever unit your tape uses.
- Sister sizes included: See alternate sizes with the same cup volume for a better fit.
- Clear guidance: Each input explains exactly where and how to measure.
- Free and private: No signup needed to get your size.
Frequently Asked Questions (FAQ)
Is the Bra Size Calculator free? Yes. It is completely free with no signup.
How accurate is the result? It is a solid estimate based on standard US sizing math. Fit varies between brands, so always check the sizing chart of the brand you are buying from.
What are sister sizes? Sister sizes keep the same cup volume while changing the band. If the band feels tight but the cup fits, a sister size up in band and down in cup often fits better.
Should I measure with a bra on? Measure the bust while wearing an unpadded bra for the most reliable number, and the underbust directly on skin.
Why does my size differ between brands? Brands cut differently and use slightly different grading. Your calculated size is the starting point, and reviews help you fine tune from there.
Do I need to create an account? No. The calculator works instantly with no signup.
More Health and Fitness Tools
Explore the calculators collection, check the Percentage Calculator, and try the Average Calculator.