UK Bra Size Calculator
Use this calculator to determine your estimated UK bra size. Accurate measurements are key to finding a comfortable and supportive bra.
Measure tightly around your ribcage, directly under your bust.
Measure around the fullest part of your bust, keeping the tape level.
Your Estimated UK Bra Size:
Understanding Your UK Bra Size: A Comprehensive Guide
Finding the right bra size is crucial for comfort, support, and overall breast health. An ill-fitting bra can lead to discomfort, back pain, poor posture, and even skin irritation. The UK bra sizing system, while widely used, can sometimes be confusing. This calculator and guide aim to demystify the process, helping you find your perfect fit.
Why is Accurate Bra Sizing Important?
- Comfort: A well-fitting bra won't dig in, gape, or ride up.
- Support: Proper support reduces strain on your back and shoulders.
- Appearance: The right bra enhances your silhouette and makes clothes fit better.
- Breast Health: Good support can help prevent ligament stretching and discomfort.
How to Measure for Your UK Bra Size
You'll need a soft tape measure and ideally, a non-padded, unlined bra or no bra at all for the most accurate results. Stand upright and relax.
Step 1: Measure Your Underbust (Band Size)
- Wrap the tape measure firmly around your ribcage, directly underneath your bust.
- Ensure the tape is level all the way around your back.
- Breathe out to get the smallest measurement.
- Note this measurement in inches. This is your underbust measurement.
Example: If your underbust measurement is 30.5 inches.
Step 2: Measure Your Bust (Cup Size)
- Wrap the tape measure loosely around the fullest part of your bust.
- Ensure the tape is level across your back and not too tight or too loose.
- Note this measurement in inches. This is your bust measurement.
Example: If your bust measurement is 36 inches.
How the UK Bra Size Calculator Works
The calculator uses your two measurements to determine your estimated UK bra size. Here's the logic:
1. Calculating Your Band Size
In the modern UK sizing method, your band size is derived directly from your underbust measurement. The calculator takes your underbust measurement (in inches) and rounds it to the nearest even number. This even number is your band size.
- If your underbust is 29 inches, your band size will be 30.
- If your underbust is 30.5 inches, your band size will be 30.
- If your underbust is 31 inches, your band size will be 32.
This "plus zero" method is generally preferred over the older "+4/+5" method, as it provides a snugger, more supportive band fit.
2. Calculating Your Cup Size
Your cup size is determined by the difference between your bust measurement and your calculated band size (not your raw underbust measurement). Each inch of difference corresponds to a specific cup letter:
- 0 inches difference = AA cup
- 1 inch difference = A cup
- 2 inches difference = B cup
- 3 inches difference = C cup
- 4 inches difference = D cup
- 5 inches difference = DD cup
- 6 inches difference = E cup
- 7 inches difference = F cup
- 8 inches difference = FF cup
- 9 inches difference = G cup
- 10 inches difference = GG cup
- 11 inches difference = H cup
- 12 inches difference = HH cup
- 13 inches difference = J cup
- 14 inches difference = JJ cup
- 15 inches difference = K cup
- And so on…
Example Calculation:
Let's use the example measurements:
- Underbust: 30.5 inches
- Bust: 36 inches
- Band Size: 30.5 inches rounded to the nearest even number is 30.
- Cup Difference: Bust (36 inches) – Band Size (30 inches) = 6 inches.
- Cup Size: A 6-inch difference corresponds to an E cup.
Your estimated UK bra size would be 30E.
Important Considerations and Tips for a Perfect Fit
While this calculator provides a great starting point, bra sizing isn't an exact science. Different brands can fit slightly differently, and your body shape plays a role. Always try on bras to confirm the fit.
- The Band is Key: The band provides about 80% of the support. It should be snug and level all the way around your back, not riding up. You should be able to fit two fingers comfortably under the band at the back.
- Cups Should Enclose: Your breasts should fully fill the cups without spilling over the top, sides, or bottom. There should be no gaping or wrinkling in the cup fabric.
- Gore Lies Flat: The 'gore' (the center panel between the cups) should lie flat against your sternum without lifting away from your body.
- Straps are Supportive, Not Sole Support: Bra straps should feel comfortable and not dig into your shoulders. They are there to keep the cups in place, not to provide the main lift.
- Scoop and Swoop: When trying on a bra, lean forward and scoop all your breast tissue from under your arms and from the bottom of the cups into the cups.
- Sister Sizes: If your calculated size isn't quite right, you might try a "sister size." For example, if you're a 34C, your sister sizes are 32D (smaller band, larger cup) or 36B (larger band, smaller cup). The cup volume remains similar, but the band changes.
- Professional Fitting: For the most accurate results, consider visiting a professional bra fitter. They can offer personalized advice and help you navigate different styles and brands.
This calculator is a helpful tool to guide you, but remember that the ultimate test is how the bra feels and looks on your body.