18B Bras

Discover perfectly fitted 18B bras designed for your body proportions. From everyday essentials to beautiful lace styles, find comfortable, flattering bras that celebrate your shape with confidence.

Shop 18B Bras - Full Size 18B Collection

Finding bras in size 18B can be surprisingly challenging. Many retailers overlook this combination of band 18 with a B cup, assuming larger bands always pair with larger cups. At Illusions Lingerie, we understand that every body is unique. Our Melbourne boutique stocks a thoughtfully curated selection of 18 band bras across all cup sizes, including B cup options that provide the right balance of band support and cup coverage. Whether you're after seamless t-shirt bras for everyday wear, comfortable wirefree styles, or elegant lace designs, we carry quality brands that truly understand proportional sizing. Many customers discover they're actually a 18B after years of wearing ill-fitting 16C or 20A bras sister sizing can make a significant difference to comfort and shape. Visit our Melbourne store for a complimentary professional bra fitting with our expert fitters who will confirm your size and recommend styles that work beautifully for your body. Our B cup collection spans band sizes 8 through 30, giving you options to explore the perfect fit.

What size is 18B in bras?

Size 18B is an Australian bra size with a band measurement of approximately 98-102cm (measured snugly under the bust) and a B cup, which indicates a 15cm difference between your underbust and bust measurements. This size suits women who need a supportive 18 band with moderate B cup volume. If you've been wearing 16C or 20A and find the band too tight or too loose respectively, 18B might be your ideal sister size.

Visit our Melbourne store for a complimentary professional bra fitting with our expert fitters who will help you find your perfect size and style. No bookings required - just drop in during store hours. We stock band 18 bras in cup sizes A through K.

What are the sister sizes of 18B?

The sister sizes of 18B are 16C (one band size down, one cup size up) and 20A (one band size up, one cup size down). Sister sizes have the same cup volume but different band lengths, which can be helpful if you find your 18B band slightly too loose or too tight. If the 18B band feels loose but the cups fit well, try 16C for a firmer band. If the 18B band feels snug, try 20A for extra band room while maintaining the same cup volume.

How do I know if I need 18B or 18A?

The difference between 18B and 18A is one cup size - B cup has approximately 2.5cm more volume than A cup. If your 18A bras have spillage, visible breast tissue at the sides, or your nipples aren't centred in the cups, you likely need 18B instead. Conversely, if your 18B bras have gaping or wrinkling in the cups, you might be more comfortable in 18A. The band size stays the same; only the cup volume changes.