20K
20K Bra Size – Find Your Perfect Fit
Find Your Perfect Fit in Size 20K Bras
Size 20K? We’ve got you covered with expertly curated, comfortable and stylish bras that actually fit. At The Foundation, we believe every body deserves supportive, stylish, and high-quality lingerie. Our 20K bra collection is carefully curated to deliver just that—comfort and confidence in a size that understands you.
What Does 20K Mean? Let's Break It Down
A 20K bra size combines a band size of 20 (based on Australian sizing) with a K cup, which indicates a substantial cup volume. The band size refers to the measurement around your torso, just under your bust, and the cup size represents the difference between your bust and underbust measurements.
In simple terms: the higher the letter, the fuller the bust in proportion to the band. Size 20K is designed for fuller-busted individuals with a smaller underbust circumference compared to cup volume—and finding the right support here is absolutely essential.
International Size Conversion Chart
| Region | Band Size | Cup Equivalent |
|---|---|---|
| Australia (AU) | 20 | K |
| UK | 42 | H (Approximate) |
| US | 42 | I (Approximate) |
| EU | 95 | K |
| France (FR) | 110 | K |
Note: Cup sizes don’t convert perfectly across regions. These conversions are only approximate, as international sizing standards vary. For the best accuracy, we recommend consulting our expert fitters or using our in-store fitting service before making a purchase. Always refer to our Size Chart for best fit.
How to Measure Your Bra Size at Home
Need help with your bust measurement, band size or figuring out your cup size? Our bra fitting guide is here to help. Grab a tape measure and follow the steps below
- Band Size: Wrap the tape measure snugly under your bust. Ensure it’s level and firm. Round to the nearest whole number.
- Bust Measurement: Measure around the fullest part of your bust. Keep the tape comfortably snug.
- Cup Size: Subtract the band measurement from the bust measurement. Each inch difference equals one cup size. E.g., 122cm bust - 102cm underbust = 20cm = K cup.
Example: If your bust is 122cm and your underbust is 102cm, the 20cm difference aligns with a K cup
Understanding Sister Sizes
Sister sizes are handy if your exact size isn’t available. For 20K, you might also try:
- 18KK: Slightly tighter band, same cup volume
-
22JJ: Slightly looser band, same cup volume
These sizes maintain a similar cup volume while adjusting the band size for flexibility.
Best Bra Styles for 20K
Support and comfort are non-negotiable at this size. Each style in our collection is chosen to meet specific needs faced by 20K wearers:
- Full Cup Bras: Excellent for full bust coverage and support. They distribute weight evenly and reduce bounce, making them ideal for everyday wear.
- Lightly Padded Bras: Offer shape without adding volume, while cushioning the bust and preventing nipple show-through. Great for smoothing and balancing your silhouette.
- Wireless Bras: Provide gentle lift and flexibility without digging in, especially beneficial for those who experience pressure or discomfort from underwires.
- Seamless Bras: Deliver a smooth line under clothes, preventing visible bra outlines. These are perfect for fitted tops and dresses.
- Lace Bras: Bring elegance without compromising support. Many feature structured lining beneath delicate fabric for beauty and practicality.
-
Sports Bras: Designed for bounce control and breast stability during movement, easing strain on shoulders and back.
Many of our bras feature deep, high-cut cups to encapsulate the bust without spillage, and upright wires for structured support that sits flat against the chest.
Featured Brands in Size 20K
● Prima Donna
Why Shop 20K with The Foundation?
- Expert Curation: Only bras that pass our comfort + quality checks
- Inclusive Fit Range: From petite to fuller figures
- Helpful Support: Size Guide, Contact Us
- Hassle-Free Returns: Returns Policy
- Bra Fitting Experts: In-store and Online Bra Fitting
- Customer Service: Dedicated team to support you
"Finally found a bra that fits and feels amazing—thank you The Foundation! The staff truly understand what support means." — Emily, VIC
Shop Now
Browse our 20K bras now and discover your new favourites.
FAQs
Is 20K a common bra size in Australia?
Not particularly, but it’s increasingly recognised. Nearly 1 in 5 Australian women wear a D cup or larger. We're leading the way in inclusive sizing.
What should I do if my 20K size is sold out?
Try sister sizes like 18KK or 22JJ, or contact our team for fitting support.
How often should I remeasure my bra size?
At least once a year or after any body changes. Use a tape measure or visit us in-store.
Are wireless bras supportive enough in size 20K?
Absolutely when designed well, wireless bras can provide fantastic lift and comfort.
Can I return a bra if it doesn’t fit?
Yes! As long as it's unworn with tags, you're eligible for exchange or credit. See full return policy.