18J
18J Bra Size – Find Your Confident Fit
Understanding the 18J Bra Size
Shopping for a bra size like 18J shouldn’t be complicated. The 18J is a combination of a band size 18 (equivalent to AU size 40) and a J cup size, ideal for women with a fuller body size and bust. This size offers support, structure, and comfort for daily wear, active lifestyles, and everything in between. If you’ve struggled to find the right fit, our expert team at The Foundation is here to help with personalised bra fitting support both online and in-store.
We specialise in fuller bust lingerie and proudly carry a wide range of bra sizes designed with innovation and comfort in mind.
Not sure what to choose? Explore best selling bras, sort options by low to high or high to low in price, or filter by new to old to find the latest arrivals. Shopping for bra sizes has never been easier.
International Size Chart
| Region | Band Size | Cup Size |
|---|---|---|
| Australia (AU) | 18 | J |
| UK | 40 | GG |
| USA | 40 | J |
| EU | 90 | K |
| France (FR) | 105 | K |
How to Measure Your Bra Size
Getting your correct bra size is easier than you think. All you need is a tape measure and a few minutes.
- Band Size: Measure snugly around your ribcage, directly under the bust. 102 cm (40 inches) aligns with an AU size 18 band.
- Bust Measurement: Measure around the fullest part of your bust.
- Cup Size: Subtract band from bust measurement to find your cup size.
Need more support? Use our Size Chart or Contact Us to speak to our fitting experts or book a virtual bra fitting service.
Sister Sizes & Fit Flexibility
If your usual size isn’t available, sister sizes are a helpful workaround. These offer the same cup volume with a different band size for a more customised fit:
Sister sizes are ideal if your bra feels slightly too tight or loose in the band.
Best Bra Styles for 18J
Support and style go hand in hand with these highly recommended styles for an 18J bra size
- Full Cup Bras: Offer coverage with side slings and reinforced seams.
- Wireless Bras: For gentle, all-day comfort.
- Seamless Bras: Disappear under clothing.
- Strapless Bras: Stay in place with supportive 3-hook underbands.
- Sports Bras: From Low Impact to High Impact, find your match via Sports Bras Direct.
- Nursing Bras: Comfortable support for breastfeeding.
Brands That Stock 18J
Our featured lingerie brands are committed to supporting fuller busts. All options in this size are chosen for quality, comfort, and innovation:
- PrimaDonna – Luxury craftsmanship and beautiful finish
- Panache – Reliable everyday support with style
- Elomi – Thoughtfully designed for curves
- Samanta – Polish-made fashion-forward support
Many of these designs feature Forgiving Fit technology and are loved in our customer reviews for their comfort and long wear life.
Why Shop With The Foundation?
Enjoy Free Exchanges, 100 Day Returns, expert bra fitting, customer service and our physical locations. Sign up to be the first to know about special offers and latest news.
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FAQs
What is an 18J bra size in Australian sizing?
It combines a band size of 18 (around 102 cm) with a J cup, designed for fuller busts and bodies.
Do you offer maternity or nursing bras in 18J?
Yes! Check our nursing bras range for supportive and easy-access options.
Can I return my bra if it doesn’t fit?
Yes. We offer Free Exchanges and 100 Day Returns. See our return policy.
Do sizes vary across brands?
Yes, we recommend checking the Size Guide and exploring sister sizes.
Do you offer in-store fittings?
Yes, visit our Rozelle or Neutral Bay stores for D-K cup bra-fitters.