The Real Guide to Finding Your Perfect Bra Size (Without the BS)

Because your body deserves better than guesswork, outdated rules, and “that’ll do” lingerie.

Bra fitting has become one of those topics where everyone seems to have an opinion — and most of those opinions are… questionable at best. If you’ve ever walked into a store, been measured over your clothes, handed a size that “should fit most people,” and still walked out feeling uncomfortable, unsupported, or straight-up confused, you’re not alone.

Across Australia, the biggest pain point we hear from women, femmes, and non-binary babes is always the same:
“I don’t actually know my real bra size - and nothing ever fits properly.”

So today, we’re doing what Dream & Drive Lingerie does best: stripping back the fluff, ditching the outdated rules, and giving you an honest, no-BS guide to finding your perfect bra size.
This is the guide we wish we’d had when we started designing inclusive lingerie in sizes XS–4XL and 8A–22E. This is for you - the human being inside the bra - not the fit model brands have historically designed around.

Let’s get you supported properly, shall we?

Why Bra Sizing Feels So Hard (Spoiler: It’s Not You)

Here’s the truth mainstream brands don’t like to talk about:

Most people are wearing the wrong bra size because bra sizing systems were never designed to be accurate in the first place.

Seriously.

Traditional sizing was built decades ago around limited body types, narrow cup grading, and a “close enough” mentality. Add in vanity sizing, brand-to-brand inconsistencies, and the rise of stretchy bralettes… and suddenly nobody knows what size they actually are.

Let’s break down the biggest myths that are still messing with your lingerie drawer.

Common Bra Sizing Myths — Debunked

Myth 1: “A D cup is huge.”

Nope. Cup size is relative to band size.
An 8D and a 16D are completely different volumes — the D simply tells us the difference between your underbust and full bust.

Cup letters don’t define your body. They define a measurement.
You are not “a D.” You are a person who fits a particular combination of band + cup.

Myth 2: “Your bra size is the same across all brands.”

We wish.
The reality: brands use different patterns, moulds, materials, and grading rules.

This means:

• You might be a 12C in one brand

• A 10D in another

• And a 14B in a stretchy bralette

None of this means you’re “wrong” or mismeasured. It just means brands grade differently.

At Dream & Drive, we’re open about this because we believe in transparency — not tricking you into thinking the issue is your body.

Myth 3: “If the band feels tight, size up.”

Sometimes true - but often, tightness is a sign of:

• Bands that aren’t designed for movement

• Cheap materials that dig

• Or cups that are too small, forcing the band to overwork

A well-designed band should feel comfortably firm, not suffocating.
Firm = support.
Painful = bad patterning or wrong size

Myth 4: “You should replace your bras every 6–12 months.”

You should…
But most people don’t because finding a new one feels overwhelming.

When you know your real size, buying bras suddenly gets easier - and you stop hanging onto uncomfortable ones because “it kind of fits.”

Myth 5: “Measuring tapes give you an exact size.”

A tape measure gives you a starting point, not an absolute truth.

Your breast tissue density, chest shape, strap width, and fabric stretch all change how a bra fits.
This is why two people with identical measurements may need different cup sizes.

Tape measures can’t detect:

• Side fullness

• Projection

• Root width

• Breast asymmetry

• High-set vs low-set breasts

• Soft vs firm tissue

But you can - once you know what to look for.

Let’s Measure: The Dream & Drive No-BS Bra Sizing Method

You’ll need:

• A soft measuring tape

• A mirror

• A non-padded bra (or no bra if you’re comfortable - it can give a clearer reading)

Step 1: Measure Your Underbust (Your Band Size)

This is the measurement under your breasts, where your bra band sits.

1. Exhale normally — don’t suck in

2. Wrap the tape firmly around your ribcage

3. Keep the tape parallel to the floor

4. Note the number (in cm)

Australian band conversion (approximate):

• 68–72 cm → 8

• 73–77 cm → 10

• 78–82 cm → 12

• 83–87 cm → 14

• 88–92 cm → 16

• 93–97 cm → 18

• 98–102 cm → 20

• 103–107 cm → 22

Your band should feel secure — it provides 80–90% of your bra’s support.

Step 2: Measure Your Full Bust (Your Cup Size)

Wrap the tape loosely around the fullest part of your bust.

Key detail:
Don’t pull the tape tight.
You want to measure your shape, not compress it.

Record the number.

Step 3: Calculate Your Cup Size

Subtract your underbust from your full bust measurement.

The difference (in cm) generally aligns with:

• 10–11 cm → A

• 12–13 cm → B

• 14–15 cm → C

• 16–17 cm → D

• 18–19 cm → DD/E

• 20–21 cm → F

• 22–23 cm → G

This is your starting point, not the final answer.

Step 4: Check the Fit — The Only Step That Truly Matters

A bra either fits your body or it doesn’t.
Here’s what to look for:

The Band

• Sits horizontally across your back

• Doesn’t ride up

• Feels firm but breathable

• You can fit two fingers underneath comfortably

If it rides up → band too big
If it digs painfully → band too small OR poor design

The Cups

The right cup will:

• Contain all tissue (no double-boob)

• Sit flat at the centre gore (the bit between the cups)

• Have no gaping

Quad-boob = cup too small
Gaping = cup too big OR moulded cup shape doesn’t match your breast shape

The Straps

Straps should:

• Sit comfortably without digging

• Not carry all the weight (that’s the band’s job)

• Stay in place

If they fall down, you might have:

• Narrow shoulders

• Shallow upper breast fullness

• A bra style that doesn’t suit your shape

Understanding Breast Shapes (And Why It Affects Sizing)

You can absolutely have the same measurements as someone else and still wear a different size because breast shape matters.
Here are the most common ones:

1. Full-on-top

More fullness at the top → often needs more cup depth
Best fits: balcony, plunges with stretch lace

2. Full-on-bottom

More volume lower → often gaps at the top in rigid cups
Best fits: full cups, soft fabrics, triangle styles

3. East–West

Nipples point outward → may need side support
Best fits: bras with side panels or supportive wiring

4. Projected

Breasts project forward → needs deeper cups
Best fits: bras designed with forward projection

5. Shallow

Wide root, less projection → many moulded cups gape
Best fits: bralettes, soft cups, stretch lace

6. Asymmetrical (very common!)

One breast is larger → always fit the bigger one
Best fits: stretch cups, adjustable styles

At Dream & Drive, our size range (XS–4XL, 8A–22E) and flexible materials are designed to adapt to these shapes - not force you into one.

Why Your Size Changes - Even If Your Weight Doesn’t

Bras aren’t like shoes - they shift with your life.

Your size can change because of:

• Hormones

• Your cycle

• Salt intake

• Stress

• Medications

• Pregnancy and breastfeeding

• Breast tissue softness

• Strength training

• Age

• Contraception

Your body evolves.
Your size evolves.
That is normal and healthy.

How Different Brands Will Size You Differently (And Why It’s Not Your Fault)

Let’s be brutally honest:
Many mainstream brands design around a single “fit model” — usually a firm, evenly full, average-height body with symmetrical breasts.

Which… is almost no one.

This leads to:

• Bands that dig into soft bodies

• Cups that assume firmness

• Straps that fall off narrow shoulders

• Cups that rely on shallow shapes

At Dream & Drive, our patterns are built around real bodies, real softness, and real variation.
We also test fit on multiple sizes, not just one.

Your bra should adapt to you, not demand the opposite.

Sizing Across Brands: What to Expect

Here’s what might shift when you try different labels:

Band sizes

Some brands run tighter (European styles), while others run stretchy (budget Australian retailers).

Cup grading

Some brands increase cup volume gradually.
Others jump dramatically between sizes.

Fabric & construction

Stretch lace vs rigid lace changes everything.

Style

A plunge in one brand might fit you…
A plunge in another may gape or cut in.

This is why we always say:
You don’t have one bra size. You have a size range that works for your body.

And that’s okay.

How to Choose Bras for Your Body Type

If you have a fuller bust (DD+)

• Look for wider bands

• Soft stretch cups help avoid cutting in

• Side support is your friend

• Avoid moulded cups if they don’t match your shape

If you have a smaller bust (A–C)

• Triangle styles work beautifully

• Stretch lace = more forgiving fit

• Cup shape matters more than cup size

• Don’t size up “for more cleavage” — fit creates shape, not padding

If you have a broader torso

• A larger band doesn’t mean a “bigger body”

• Many people with athletic builds need bigger bands and smaller cups

• Cup volume changes with each band — remember sister sizing

If you’re plus size

• Comfort is essential, not optional

• Soft materials, wide bands, and adaptable cups make the world of difference

• Don’t settle for bras that dig or roll — that’s a design problem, not a you problem

If you’re petite or short

• Short straps are key

• Cups with lower wires prevent digging

• Bands need to sit flat without pinching

If you’re curvy with a small band size

• Sister sizing is your superpower

• You may need styles that accommodate projection and fullness

Sister Sizing: The Secret Weapon Everyone Should Know

If a bra almost fits, sister sizing can solve it.

Your sister sizes:

• Go up a band, down a cup (e.g., 10D → 12C)

• Or down a band, up a cup (e.g., 12C → 10D)

Same cup volume, different band length.

Use sister sizes when:

• The cups are perfect but the band is too tight/loose

• The style you want is sold out in your exact size

• You’re between sizes

Fit Problems & How to Fix Them

Problem: Cup spillage

Solution: Go up a cup OR switch to stretch lace styles.

Problem: Band riding up

Solution: Go down a band.

Problem: Gaping in cups

Solution: Try a smaller cup OR switch styles (likely shape mismatch).

Problem: Straps falling down

Solution: Adjust straps OR switch to a style with closer-set straps.

Problem: Centre gore lifting

Solution: Go up a cup size OR choose a plunge style if you have close-set breasts.

Why Inclusive Sizing Matters (And Why We Fight For It)

Sizing shouldn’t be exclusive.
Bodies shouldn’t be made to feel wrong.
Lingerie shouldn’t be designed around a single narrow ideal.

Dream & Drive was built so you can:

• Feel seen

• Feel supported

• Feel like your body is never the issue

Our sizes XS–4XL and 8A–22E exist because real people deserve lingerie that loves them back.

You deserve to look at a size chart and feel included — not “almost included.”

Want the Perfect Fit? We Can Help.

If you’ve ever second-guessed your size, ordered multiple bras only to return them all, or thought, “Maybe my body is just weird” please hear this:

Your body is not the problem.
Your bras have been failing you.

We offer:

Free Custom Fitting Recommendations

Send us your measurements and a photo of a bra you currently wear (optional). We’ll recommend your Dream & Drive size plus your sister size. Simply contact us (we're super friendly).

Flexible Size Exchange Policy

If your bra isn’t perfect, we’ll help you find the one that is - no judgement, no fuss.

Inclusive Designs Made for Real Bodies

Soft materials, forgiving fabrics, and patterns made for comfort and beauty.

Final Word: Your Perfect Fit Exists -
And It’s Not As Complicated As You’ve Been Told

Finding your perfect bra size isn’t about memorising numbers, following rigid rules, or squeezing into sizes that don’t honour your body.

It’s about:

• Understanding your shape

• Learning what comfort actually feels like

• Choosing bras designed for real humans

• And knowing you deserve lingerie that supports your life — not restricts it

Your bra should empower you, not fight you.

And if you ever need help, we’re right here. Every one of our products has sizing info to help you along the way.
No BS, no judgement - just beautiful lingerie made with purpose.