MTF Bra Size & Breast Form Calculator
Find your bra size and breast form size with our calculator designed for trans women, transfeminine people, crossdressers and anyone with an AMAB body shape. Enter your measurements to estimate your Australian bra size and see how different breast form sizes can change your finished bust size.
Your measurements
Measure without breast forms, then select the pair you plan to wear.
Measure firmly around your ribcage directly under your chest.
Measure around the fullest part of your chest while standing. This cannot be lower than your underbust.
Breast form size
Weight shown is the combined weight of the pair.
Estimated size
with 400g breast forms
Estimate only. This calculator is designed to provide a starting size, not a guaranteed fit. We’ll continue to refine it as we gather more fitting data. Bra shape & breast-form positioning can all affect your best size.
How to Measure Your Bra Size
1. Measure Your Underbust
Wrap a measuring tape snugly around your ribcage directly underneath your chest to find your underbust measurement.
2. Measure Your Overbust
Measure around the fullest part of your chest along your nipple line while keeping the tape level to calculate your overbust size.
3. Add Your Breast Form Size
Select your breast form size to estimate how your chosen forms may change your overbust measurement and finished bra size.
Visit Us In Store
Browse our range of products in-store
with the help of the expert fitting staff at:
Illusions Lingerie
22 Puckle St,
Moonee Ponds,
VIC 3039
Australia
📞 (03) 9326 1543
🕐 Mon - Sat : 9am - 4pm
Bra Size Calculator for Trans Women
Bra sizing can differ for trans women because chest shape, breast development and body proportions may not always align with standard AFAB bra size calculators. Our MTF bra size calculator is designed to give people assigned male at birth a more useful starting point based on underbust and overbust measurements, with the option to calculate your size with or without breast forms.
Crossdressing Bra Size Calculator
If you’re crossdressing, your ideal bra size may depend on both your natural chest measurements and the breast forms you choose to wear. Our crossdressing bra size calculator helps estimate a suitable bra size while showing how different breast form sizes can affect your overall bust measurement, making it easier to choose the look and fit you want, from subtle and natural to a fuller, bustier shape.
FAQ
Below are some answers to commonly asked questions from our customers.
Are bra fittings free?
Are bra fittings free?
Yes, our professional fittings are completely free.
Our experienced fitters are here to help you find the right size, style and products in a comfortable, welcoming environment.
Note: As a small boutique, our fittings are intended for customers who are genuinely looking to purchase on the day.
Do I need to make a booking?
Do I need to make a booking?
No booking is required. We offer walk-in fittings during our store hours, with friendly and experienced fitters ready to help.
When is a good time to visit?
When is a good time to visit?
Weekday mornings are generally quieter if you prefer a more relaxed and private shopping experience.
Are men allowed in store?
Are men allowed in store?
Absolutely. Everyone is welcome at and we regularly assist men, crossdressers, transgender customers and partners looking for the right fit.
Is shipping discreet?
Is shipping discreet?
Yes. All online orders are sent in plain packaging with no indication of the contents.
Can I pay cash?
Can I pay cash?
Yes, cash and EFTPOS payments are available in-store. AfterPay is not available in store.