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Cosmetic Surgery

How to Choose Breast Implant Size

A guide to breast implant sizing at Aesthetica Image Centre — including Dr Tony Prochazka's 45:55 proportion guideline, implant profile, and the factors that shape your final result.

At a Glance

Choosing Your Breast Implant Size

Sizing Guideline The 45:55 breast proportion guideline — approximately 45% volume above the nipple, 55% below, for a natural contour
Measured In Cubic centimetres (cc) — but volume alone doesn't determine the final look
Also Considered Implant profile (low, moderate, high), chest width, natural tissue, skin elasticity and lifestyle
Who Decides A collaborative decision between you and Dr Tony Prochazka, based on your anatomy and goals
Related Guides Read alongside our guides to Breast Implants and Implant Placement Options

This page is a general guide. Your ideal size and profile are determined together with Dr Tony during your personal consultation.

Choosing the right breast implant size is one of the most important decisions in breast augmentation. The ideal size depends on your body proportions, lifestyle, and aesthetic goals.

At Aesthetica Image Centre in Armadale, Melbourne, we guide you through this process with personalised assessment and careful planning to help you achieve a balanced, natural-looking result.

Size is one part of a bigger picture — profile, placement and your own anatomy all shape the final outcome.

If you're exploring your options, you may also wish to read our guide to Breast Implants in Melbourne.

Dr Tony's Approach

The 45:55 Breast Proportion Guideline

The 45:55 breast ratio is an aesthetic guideline often referenced in breast surgery when considering implant size. It suggests that a natural-looking breast may have approximately 45% of its volume above the nipple (upper pole) and 55% below (lower pole).

Upper Pole (45%)

A gentle slope above the nipple, avoiding an overly full or "augmented" look in the upper breast.

Lower Pole (55%)

Slightly fuller to create a natural contour, echoing the way volume naturally sits in an unaugmented breast.

This concept, based on the work of Dr Tony Prochazka, is used as a visual guide rather than a fixed rule when considering your breast implant size — helping to achieve a balanced and proportionate result rather than a purely numerical one.

Beyond the Number

Breast Implant Size Is More Than Volume

Breast implant size is often measured in cubic centimetres (cc), but choosing the right size isn't simply about selecting a number. Factors that influence implant size include:

  • Your natural breast tissue and chest width
  • Your height and overall body proportions
  • Skin elasticity and breast shape
  • Your lifestyle and activity level
  • Your personal aesthetic preferences

Dr Tony Prochazka will consider all of these factors when helping you choose a size that complements your body. The final result is also influenced by how implants are positioned — you can learn more in our guide to implant placement options.

Understanding Profile

Implant Profile and Shape

In addition to volume, the implant profile affects how your breasts will look. Two implants of the same size (cc) can create quite different results depending on profile.

Aesthetica breast implant size profiles with the same volume, showing low, moderate and high profile differences

Low Profile

Wider at the base, with a more subtle projection forward — often chosen for a fuller-figured, natural look.

Moderate Profile

A balance of projection and width, suiting a broad range of body types and goals.

High Profile

More forward projection with a narrower base — often chosen by patients with a smaller chest width seeking more visible fullness.

Profile selection works together with size to achieve your desired outcome — one without the other tells only part of the story.

What To Expect

How Sizing Is Approached at Consultation

Choosing a size is a collaborative process, not a single decision made in isolation. At your consultation, Dr Tony will:

  • Assess your natural breast tissue, chest width and body proportions
  • Discuss your goals, lifestyle and any concerns about scale or projection
  • Explain how the 45:55 guideline applies to your individual anatomy
  • Talk through implant profile options alongside size
  • Answer your questions honestly, including where a particular size may not be advisable for your frame

Bringing reference images of the general look you're hoping to achieve can be a helpful starting point for this conversation.

An Honest Conversation

Setting Realistic Expectations

Every patient's anatomy is different, and results vary between individuals. During consultation, Dr Tony will discuss what may be achievable for your specific anatomy and guide you towards a suitable option — including being honest if a particular size or profile isn't likely to give you the result you're hoping for.

A real person, not a chatbot

Ask Julie

Not sure where to start with sizing? I'm Julie Bates, Aesthetica's Patient Care Coordinator. Our online chat is answered by our friendly staff — no AI, no call centre — so you're always talking to a real person, at your own pace.

Common Questions

Frequently Asked Questions

It suggests a natural-looking breast has around 45% of its volume above the nipple and 55% below. It's used as a visual guide during consultation, based on Dr Tony Prochazka's approach, rather than a fixed rule applied to every patient.

Not necessarily — implant profile and your own chest width and tissue play a major role too. Two implants with the same cc volume can look quite different on the same person depending on profile, which is why size and profile are always discussed together.

Your consultation is the place to discuss this in detail with Dr Tony, including practical ways to visualise different sizing options for your frame. He'll talk you through what's available and most useful for your specific decision.

Yes, size and placement are considered together, not separately. Larger implants or those with limited natural tissue coverage may influence which placement and incision approach is most suitable — this is covered in our guide to implant placement options.

Yes — breast implants, particularly saline and rounder profiles, can shift and look different depending on position. This is normal and something Dr Tony can explain in the context of your chosen implant type during consultation.

Reference images of the general look you're hoping to achieve are often more useful than a specific cc number alone. Dr Tony can then translate that goal into a size and profile appropriate for your individual anatomy.

Meet the Team

Your Breast Implant Doctor

Dr Tony Prochazka, Cosmetic Doctor at Aesthetica Image Centre
Cosmetic Doctor

Dr Tony Prochazka

MBBS (Melb), FACCSM (Med), FCPCA · AHPRA MED0001181976

Over 20 years' experience in cosmetic medicine and surgery-related procedures, with a focus on breast augmentation, liposculpture, fat transfer, thread lifting, blepharoplasty, facelift and facial rejuvenation. Former Inaugural Dean of the Faculty of Medicine at the Australasian College of Cosmetic Surgery, and former Vice-President of the Cosmetic Physicians Society of Australasia.

Why Choose Us

Why Aesthetica Image Centre

For over 20 years, Aesthetica Image Centre has been trusted for our:

  • Thoughtful, unrushed consultations focused on your individual anatomy
  • An honest approach to sizing — including when a smaller or larger option may suit you better
  • Warm, caring and empathetic approach
  • Convenient Armadale location
  • Personalised aftercare and ongoing support

Book Your Consultation

If you'd like to discuss breast implant sizing with Dr Tony, this is best done by calling, texting or emailing. If you're early in your research, we invite you to book a complimentary consultation with our patient care team — without pressure or obligation.

Book Your Appointment Online

Full contact details, opening hours and our enquiry form are below.