Over the past twenty years of teaching how to fit bras by eye, without a tape measure, I have emphasised the importance of not only finding the correct bra size for each person, but also allowing time when assessing the correct bra fit. Taking time not only ensures we find the right style and size for each person but we find the most comfortable bra for them because Comfort Always Wins." Lindsey Brown
Introducing our new Sister Sizing and Cross-Grading Guide for bra fitters
Introducing our new Sister Sizing & Cross-Grading Guide
When you’re working with bras every day, understanding how sizes relate to one another is essential. But switching between brands, band sizes and international sizing systems can still raise questions.
Our new Professional Bra Fitting Sister Sizing & Cross-Grading Guide is designed to give newcomers to the industry and bra fitting professionals a practical reference they can return to whenever they need a little clarity.
Created by Lindsey Brown, founder of The Bra Fitting Course, the guide draws on her more than twenty years of lingerie industry experience and a Master’s research degree in design specialising in contour design. This £25 digital download brings together explanations, sizing charts, worked examples and printable tools in one 28-page PDF.
Understanding sister sizes beyond the label
Sister sizing involves understanding the relationship between band size, cup size and cup volume. Professional cross-grading builds on that knowledge, helping you understand how related sizes sit within a sizing system.
What’s inside?
The PDF includes 25 pages of content covering bra sizing, cup volume, sister sizing and professional cross-grading principles. You’ll find UK cup progression, including double-letter sizing, alongside UK, European, USA, French and Australian size comparisons.
Worked examples and a self-test with answers help you check your understanding. Customer scripts offer practical wording for explaining sister sizes, while comparison charts cover UK cup sizes A to K across bands 28 to 50.
For everyday reference, there’s also a printable Brand Comparison Worksheet and a quick-reference sheet to keep at the till or within your mobile bra fitting kit.
Who is it for?
This guide is designed for bra fitters, mobile bra fitters, lingerie boutique owners, retail teams, fashion stylists and lingerie design students.
A reference guide, not a fitting course
This is a professional sizing and cross-grading reference, rather than a step-by-step bra fitting guide. It does not teach a tape-measure sizing method or Lindsey’s non-tape-measure fitting technique, which is taught separately through The Bra Fitting Course.
If you’re looking for a practical resource to support your sizing knowledge, explore the Professional Bra Fitting Sister Sizing & Cross-Grading Guide.
Available for £25 as a downloadable PDF. No physical product will be posted.
Each purchase includes a single-user licence for personal and professional reference. The guide may not be resold, reproduced or redistributed.
2026 — Twenty Years of Excellence
The Bra Fitting Course celebrates twenty years of bra fitting training this October. Over the years, we’ve trained women worldwide, from boutiques to brands, teaching professional bra fitting by eye without a tape measure. Our unique technique, devised by Lindsey Brown, remains at the heart of our training. Through Lindsey’s continued research, the technique remains consistent while her knowledge continues to expand.