The Lingerie Advisor's free Bra Size Tools help you calculate your UK bra size, understand UK and international sizing, compare sizes between UK brands and explore bra size differences visually. Whether you're measuring for the first time, shopping across different brands or countries, or learning how band and cup sizes work together, these tools are designed to help you understand your size and shop with confidence.
Start with our Bra Size Calculator if you need to calculate your size from your measurements. Then use the International Bra Size Calculator & UK Size Guide to convert complete bra sizes between six sizing systems, understand UK sizing and browse the full international conversion charts. Compare equivalent sizes between participating UK brands with the Bra Size Converter, or compare two UK sizes visually using the Visual Comparison Tool.
Don't know your bra size?
Start with the
Bra Size Calculator
to calculate your recommended UK bra size.
Need an international bra size conversion?
Use the
International Bra Size Calculator & UK Size Guide
to convert between UK, US/Canada, European, French, Australian/New Zealand
and Japanese sizes or browse the full conversion charts.
Comparing sizes between UK brands?
Use the
Bra Size Converter
to find the equivalent size when moving between participating UK lingerie brands.
Want to compare bra sizes visually?
Explore the
Visual Comparison Tool
to compare two UK bra sizes side by side.
Comparing neighbouring cup sizes?
Browse our collection of Mini Comparison Tools for quick visual comparisons between similar cup sizes.
Whether you're measuring for the first time, comparing brands, checking international equivalents or exploring how different bra sizes look, these free tools are designed to make bra sizing easier to understand. Each tool has been created specifically for The Lingerie Advisor to help you find your best starting size and shop with greater confidence.
Our free Bra Size Calculator uses your underband and bust measurements to calculate your recommended UK bra size. It's an ideal starting point before shopping for new bras or checking your bra fit.
Our free Bra Sister Size Calculator shows equivalent bra sizes with a similar cup volume across smaller and larger band sizes. You can calculate UK sister sizes or compare international sister sizes across several sizing systems.
Use our International Bra Size Calculator to convert between UK, US/Canada, European, French, Australian/New Zealand and Japanese bra sizes. The complete UK Bra Size Guide also explains how UK band and cup sizing works and includes international conversion charts, visual resources, buying information and fitting guidance.
Our Bra Size Converter makes it easy to compare equivalent bra sizes between participating UK lingerie brands. Whether you're moving between brands such as Triumph, Freya or Fantasie, the converter helps you identify the corresponding band and cup size.
Our Bra Size Visual Comparison Tool lets you compare two UK bra sizes side by side using realistic illustrations and key measurements. It's an easy way to see how changes in band size, cup size and sister sizing affect overall breast volume, helping you understand the differences between bra sizes more clearly.
Compare neighbouring UK cup sizes using our focused Mini Comparison Tools. Each page lets you select three band-and-cup combinations within a specific cup range and view their illustrations, measurements and cup-volume relationships side by side.
Compare UK F, FF and G cup sizes across different band sizes and see how cup volume progresses through this range.
Open the F, FF & G Tool G · GG · HCompare UK G, GG and H cup sizes visually while checking their band sizes, measurements and relative cup volumes.
Open the G, GG & H Tool H · HH · JExplore how UK H, HH and J cup sizes compare across manufactured band sizes using illustrations and key measurements.
Open the H, HH & J Tool J · JJ · KCompare UK J, JJ and K cup sizes and see how both cup progression and changing band sizes affect overall volume.
Open the J, JJ & K Tool K · KK · LView illustrated UK K, KK and L cup sizes side by side and compare their measurements across available band sizes.
Open the K, KK & L Tool KK · L · LLCompare UK KK, L and LL cup sizes within the upper end of the UK cup sequence using visual examples and measurements.
Open the KK, L & LL ToolEach tool is designed for a different part of the bra-sizing process. Use the guide below to choose the best starting point for what you need.
| Bra Size Tool | Best For | What It Does | Open Tool |
|---|---|---|---|
| Bra Size Calculator | Finding a starting UK bra size | Uses your underband and bust measurements to calculate a recommended UK band-and-cup size. | Calculate Size → |
| International Bra Size Calculator & UK Guide | Converting between UK and international bra sizes | Converts complete bra sizes between six sizing systems and provides UK band and cup charts, explanations and supporting sizing resources. | Convert Size → |
| Bra Size Converter | Comparing equivalent sizes between UK brands | Helps you identify the corresponding band-and-cup size when moving between participating UK lingerie brands. | Compare Brands → |
| Bra Size Visual Comparison Tool | Comparing any two manufactured UK bra sizes | Displays two bra sizes side by side using torso illustrations, underbust measurements and fullest-bust measurements. | Compare Sizes → |
| Mini Comparison Tools | Comparing neighbouring cup-size ranges | Lets you compare three selectable bra sizes within focused cup ranges such as F–G, G–H or K–L. | View Mini Tools → |
Recommended starting point: Begin with the Bra Size Calculator if you do not know your current size. Once you have a starting size, use the guide, converter and visual tools for further comparisons.
Which bra size tool should I use first?
If you don't know your current bra size, start with our
Bra Size Calculator.
It uses your measurements to calculate a recommended UK bra size. Once you know your size, you can use our other tools to compare brands, understand sizing and explore visual differences.
What is the difference between the International Bra Size Calculator and the Bra Size Converter?
The
International Bra Size Calculator & UK Size Guide
lets you convert complete bra sizes between UK, US/Canada, European, French, Australian/New Zealand and Japanese sizing systems. It also explains how UK bra sizing works and includes conversion charts, sizing information and visual resources. The
Bra Size Converter
helps you compare equivalent bra sizes between participating UK lingerie brands, making it easier to find your size when switching from one brand to another.
Can I compare bra sizes visually?
Yes. Our
Bra Size Visual Comparison Tool
lets you compare any two manufactured UK bra sizes side by side using realistic torso illustrations, measurements and cup-volume information. We also offer focused Mini Comparison Tools for neighbouring cup-size ranges.
Are all of the bra size tools free?
Yes. Every bra size tool on The Lingerie Advisor is free to use, including the Bra Size Calculator, International Bra Size Calculator & Conversions, Bra Size Converter, Visual Comparison Tool and Mini Comparison Tools.
Can these tools help me choose a better fitting bra?
They provide a reliable starting point by helping you calculate your size, understand sizing systems and compare bra sizes. For detailed measuring guidance and fit checks, visit our
Bra Fitting Advice
page.
Continue learning about bra sizing, compare brands and find practical advice to help you understand measurements, cup sizes and bra fit.
Learn how a well-fitting bra should look and feel, recognise common fit issues and improve your bra fit.
Read Fitting Advice →Compare UK sizing across leading lingerie brands using dedicated brand size guides and conversion tables.
Browse Brand Guides →Explore the complete UK cup-size sequence from AA to LL and understand how cup volume changes.
View Cup Guide →Browse buying guides covering everyday bras, sports bras, strapless bras and recommendations by bra size.
Explore Buying Guides →