18DD Bra Size Collection
Understanding Your 18DD Bra Size
If you're wearing an 18DD bra size, here's what it really means: the number 18 refers to your band size, which typically suits a body size with a bust measurement of around 100cm under the bust. The "DD" is your cup size—indicating a fuller bust. It’s important to note that cup size refers to the volume of the bust in relation to the band size, so a DD cup on an 18 band is not the same volume as a DD on a 12 band. Combined, an 18DD offers ample support and comfort for women with a broad back and a generous bust. Getting the right size isn't just about comfort—it's about confidence and finding that perfect fit.
International Bra Size Conversion
Refer to the Conversion Table below for easy size matching globally:
| Region | Equivalent Size |
|---|---|
| Australia (AU) | 18DD |
| United Kingdom (UK) | 40DD |
| United States (US) | 40DD/E |
| Europe (EU) | 90E |
| France (FR) | 105E |
How to Measure Your Bra Size at Home
All you need is a tape measure and a few quiet moments. Here's how:
- Band Size: Measure snugly under your bust while keeping the tape straight. Round to the nearest even number. That's your band size.
- Bust Size: Measure around the fullest part of your bust—don't pull too tight.
- Subtract your band size from your bust size. A difference of 5 inches typically equates to a DD cup. This is part of accurate bra fitting and essential to getting your bra sizing right.
Need help? Visit our Size Chart, try our Bra Fit Guide or use our virtual bra fitting services to ensure a great fit.
Sister Sizes and Smart Alternatives
If you're between sizes or your favourite bra is out of stock, try these sister sizes for a comparable fit:
Sister sizes are perfect for adjusting comfort without sacrificing support, especially in the Australian sizing system.
Best Bra Styles for 18DD
The right style can make all the difference. For 18DD wearers, we recommend:
- Lightly Padded: Adds shape without bulk
- Wireless: Maximum comfort, great for everyday wear
- Seamless: Perfect under fitted clothes
- Full Cup: Offers total coverage and support—ideal for fuller bust lingerie needs
- Strapless Bras: Great under off-shoulder outfits
- Sports Bras: Choose High Impact or Medium Impact styles like the Ultimate Run Bra or Active D+ Classic
Explore options with breathable fabrics, wide front straps, side panels, contour cups, and 3-hook closures for better back and shoulders support.
Brands That Cater to 18DD at The Foundation
- Wacoal – including the gorgeous luxury t-shirt bra
- Triumph – featuring endless comfort wirefree bra, lady form soft bra, gorgeous mama wirefree bra
- Panache
- Elomi
- Berlei
- Fantasie
These brands are leaders in the lingerie industry, offering beautiful designs and reliable support for curvy bras and nursing bras alike.
Your Fit, Your Foundation
Finding your perfect bra size shouldn't be hard—it should be empowering. Our expert team is always here to help you discover your best fit, feel amazing, and shop with confidence.
Shop Now or Contact Us to get started. We offer fast shipping, easy returns, and a dedicated customer support team to make your experience seamless. SIGN UP for our newsletter to stay in the loop about new arrivals and exclusive offers!
FAQs
How do I know if 18DD is my correct size?
Use a tape measure at home or visit our fitting experts in-store. Your comfort is the best indicator!
What if I’m between sizes?
Try sister sizes like 16E or 20D. They offer similar cup volumes with slight band adjustments.
Can I return a bra if it doesn’t fit?
Check our Returns Policy. Bras must be unworn and returned within 30 days. Our in-store fitting experts are also happy to assist you with exchanges or alternative size recommendations.
Do you have a bra finder tool?
Yes! Try our Bra Finder to discover the perfect fit and style for you.
Where can I get sizing help?
Explore our fitting guide, get in touch or book a virtual fitting. It's quick, easy, and you can do it all from the comfort of home with help from our experienced fitters.