Australian Lingerie Size Chart (Complete Guide)

If you've ever ordered lingerie online and received something that didn't quite fit, you're not alone. Australian sizing can be confusing on its own — and once you start shopping international brands, things get even trickier. A US 34C isn't the same as an Australian 14C. A UK 10E is different from an Australian 10E. The differences are subtle, but they matter a lot when it comes to fit, comfort, and confidence.

This complete guide covers everything you need to know: how to measure yourself correctly, how Australian bra and lingerie sizing works, and how to convert your size when shopping from international brands. Bookmark it — you'll want to come back to this one.

Why Getting Your Lingerie Size Right Matters

A poorly fitting bra or lingerie set doesn't just feel uncomfortable — it can cause real physical issues. Wearing an unsupportive bra can lead to breast pain, as well as neck, shoulder, and back discomfort. Ill-fitting underwires dig in. Straps slip or cut into your shoulders. And if your band size is wrong, you lose almost all support, regardless of how good the cups are.

Getting your size right means more than knowing a number. It means lingerie that looks the way it's supposed to — and feels incredible to wear.

How to Measure Yourself at Home

You'll need a soft, flexible measuring tape. That's it. Take your measurements directly against your bare skin, or while wearing a thin, non-padded bra. Stand naturally — no sucking in, no expanding your chest. Two measurements are all you need.

Step 1: Underbust (Band Size)

Wrap the tape firmly around your ribcage, directly under your bust — right where the band of a bra would sit. The tape should be level and snug all the way around, but not uncomfortably tight. You should be able to slip one finger underneath. This is your underbust measurement, which determines your band size (8, 10, 12, 14, etc.).

Tip: Pull the tape firmly for this measurement. A loose underbust reading will give you a band size that's too large and cost you support.

Step 2: Overbust (Cup Size)

Wearing a non-padded bra, measure around the fullest part of your bust — usually across your nipples. Keep the tape relaxed and level, not tight. This is your overbust measurement, which helps calculate your cup size.

Tip: Keep your arms down at your sides and breathe normally. If the tape dips at the back, it won't read accurately.

Step 3: Calculate Your Cup Size

Subtract your underbust measurement from your overbust measurement. The difference (in centimetres) points you to your cup size:

Australian Bra Size Chart

Use your underbust measurement to find your band size, then apply your cup calculation above.

Australian bra band sizes typically range from 8 to 26, with cup sizes running from AA through to H and beyond in specialist ranges.

Australian Women's Underwear & Lingerie Size Chart

For briefs, knickers, thongs, and bodysuits, Australian lingerie sizing aligns with standard AU dress sizes — so if you wear a size 12 in clothing, you'll generally take a size 12 in underwear. Use your hip measurement (around the fullest part of your hips and bottom) as your guide.

Between sizes? Always size up for lingerie. A slightly looser fit is far more comfortable than digging elastic.

International Size Conversion Charts

Shopping from a US, UK, or European brand? Here's how Australian sizing translates.

Bra Band Size Conversions

Key difference: Australian and UK band numbers are the same. US bands are calculated differently — they add several inches to the underbust — so your US band number will always be larger than your Australian one.

Bra Cup Size Conversions

Important: Australian cup letters mostly align with UK sizing, but they diverge from US sizing at larger cups. A US DDD equals an Australian E. Always check cup conversions when buying from American brands.

Underwear & Lingerie Size Conversions

Understanding Sister Sizes

Sister sizes are one of the most useful concepts in bra fitting — and most women have never heard of them.

Your sister's size shares the same cup volume as your actual size, but with a different band. As the band number goes up by one size, the cup letter drops by one, and the cup volume stays the same.

For example, if your size is 12D:

• 14C = larger band, same cup volume (looser around your ribs)

• 10DD = smaller band, same cup volume (tighter around your ribs)

This comes in handy when a style you love doesn't come in your exact size, or when a band feels too tight or too loose. Trying your sister's size often solves the problem without changing how the cups fit.

Signs Your Bra Doesn't Fit Correctly

Even with accurate measurements, fit can still be off — especially across different brands and styles. Here's what to look for:

The band is riding up at the back. This means your band is too large. Try a smaller band size with a bigger cup (your sister's size).

The underwire is sitting on breast tissue. Your cup size is likely too small. Go up a cup.

The cups are gaping or wrinkling. The cup is too large, or the style doesn't suit your breast shape. Try a smaller cup or a different style.

The straps dig in or fall off your shoulders. Straps should bear only about 10–20% of the load. If yours are doing all the work, your band is too big. Adjust the straps first — if that doesn't help, go down a band size.

The centre gore (front panel) isn't sitting flat. This usually means the cups are too small. Size up.

How Sizing Varies Between Brands

Even with the most accurate measurements, bra sizing varies between brands — and often between styles within the same brand. The stretchiness of the fabric, the shape of the cups, the width of the band, and how the underwire is positioned can all affect fit.

This is perfectly normal. It's why lingerie experts recommend always trying on bras when you can, and checking the specific size notes on each product when shopping online. At Lingerie Seduction, our product pages include detailed sizing guidance to help you choose with confidence.

Tips for Shopping Lingerie Online in Australia

Always measure before you order. Even if you know your usual size, it's worth remeasuring every 12–18 months — bodies change, and so does how different fabrics and styles fit.

Check the brand's own size chart. Use our international conversion guide as a starting point, then cross-reference with the specific brand's chart. A Lingerie Seduction size 12 may fit slightly differently from a European brand's size 40.

When in doubt, size up. Especially for styles with lace, mesh, or delicate fabrics that have limited stretch. Sizing up is far more flattering than lingerie that pulls or digs.

Hip measurement for bottoms, underbust for tops. Use your hip measurement for briefs, thongs, and the bottom half of sets. Use your underbust measurement for bralettes, bra sets, and bodysuits.

Read the returns policy. If you're trying a new brand or a style you haven't worn before, make sure you understand the returns process before you order.

Frequently Asked Questions

Is Australian lingerie sizing the same as UK sizing?

For bras, the band sizes are the same, and cup letters mostly align — with minor differences at larger cup sizes. For underwear and lingerie bottoms, Australian and UK sizing use the same numerical system.

How is Australian sizing different from US sizing?

Significantly. US bra bands are calculated by adding inches to the underbust, so your US band number will always be higher than your Australian one. US cup sizing also diverges at larger sizes (a US DDD = AU E). For underwear, US sizes run several sizes smaller than AU — an AU 12 is a US 8.

What's the best way to find my size without a measuring tape?

Use your usual clothing size as a starting point for underwear and lingerie bottoms, but always check the hip measurement guide. For bras, measuring is the only reliable method — cup size, especially, cannot be estimated from clothing size alone.

Why does the same size fit differently in different brands?

Brands cut their patterns differently, use different fabrics, and have different interpretations of size standards. Always check individual product sizing notes when shopping online.

What size lingerie should I buy if I'm between sizes?

For comfort and to protect the fabric, go up a size. Most lingerie has limited stretch compared to everyday clothing.

Shop by Size at Lingerie Seduction

At Lingerie Seduction, we stock a wide range of styles across sizes — from delicate bra sets and lace lingerie through to plus-size lingerie, corsets, bodysuits, and bridal pieces. Every product page includes sizing guidance to help you shop with confidence.

Still unsure about your size? Reach out to our team — we're happy to help you find the perfect fit.