Bra Size Calculator
Use our easy bra size calculator to discover your exact size and get the comfort and support you deserve.
How to use Bra Size Calculator (Step-by-Step)
Find your perfect bra size in seconds with our easy-to-use Bra Size Calculator. This tool helps you calculate your accurate bra size based on your band size (the measurement under your bust) and bust size (the measurement around the fullest part of your chest).
Our calculator provides instant results for multiple sizing systems, including 🇺🇸 US, 🇬🇧 UK, 🇪🇺 EU, 🇫🇷 FR, 🇯🇵 JP, and 🇦🇺 AU, making it simple to find your exact fit no matter where you shop.
Select your unit (cm or inches), choose your country, enter your band and bust measurements, and click Calculate to determine your actual bra size.
What Our Bra Size Calculator Does
Our Bra Size Calculator is designed to make sizing simple and accurate. Instead of guessing or relying on old measurements, you can enter your band and bust size to get an instant result that matches your body's current shape.
This helps you find your perfect fit, whether you're shopping locally or from international brands. By removing confusion between different size charts, it helps you confidently find your bra size and choose bras that feel comfortable, supportive, and right for you.
How to Measure Bra Size with Bra Size Calculator (Step-by-Step)
Here's a simple step-by-step guide to measure your bra size accurately using our Bra Size Calculator. Just follow each step to get your perfect fit in seconds.
Get ready
Wear a lightly lined, non-padded bra. Stand tall, relax your arms, and grab a soft measuring tape.
Set up the bra size calculator
Open the Bra Size Calculator, select CM or IN, and then choose your country's sizing system (US, UK, EU, FR, JP, AU).
Measure your band (underbust)
Place the tape directly under your bust, level around your ribcage. Pull it snug, not tight. Record to the nearest ¼ inch or 0.5 cm. Enter/select this as Band Size.
Measure your bust (overbust)
Wrap the tape around the fullest part of your chest, level across your back. The tape should lie flat without squeezing. Record to the nearest ¼ inch or 0.5 cm and enter as Bust Size.
Calculate
Tap Calculate to find your bra size. You'll see your band + cup and the size in your chosen country system. You'll also see a breakdown of your band size, cup size, and country sizing system. Below your result, the tool displays sister sizes such as 38D and 42B, which have the same cup volume but different band sizes. You can try these if your current band feels too tight or too loose. Finally, a "Calculate Again" button allows you to recheck your measurements.
Why Wearing the Right Bra Size Matters
Wearing the right bra size does more than just make your clothes look better; it helps you feel comfortable, confident, and supported throughout the day. A properly fitted bra can improve your posture, prevent shoulder or back pain, and boost your overall comfort level. Many women don't realize that small differences in size can have a big impact on how a bra fits and feels.
Better Posture and Support
A well-fitted bra provides the right level of support to your bust, helping you maintain a straight and natural posture. When your band and straps fit correctly, the weight of your bust is evenly distributed, reducing pressure on your shoulders and spine. This prevents slouching and keeps you comfortable whether you're at work, walking, or relaxing.
Prevents Pain and Discomfort
Wearing the wrong size can cause digging straps, tight bands, and skin irritation. Over time, it can even lead to back, neck, or shoulder pain. The right bra size eliminates these issues by offering the right balance of snugness and flexibility, firm enough to support but soft enough to stay comfortable all day long.
Improves Shape and Appearance
The right bra can make a noticeable difference in how your clothes fit. It enhances your natural shape, gives a smoother look under clothing, and prevents common issues like gaping cups or bulging seams. Whether you're wearing a T-shirt, dress, or formal outfit, a properly fitted bra helps everything sit perfectly.
Boosts Confidence
Comfort directly affects confidence. When your bra fits properly, you don't have to adjust it constantly or worry about visible lines or slipping straps. You stand taller, feel more at ease, and move freely without distraction, a simple change that makes you look and feel your best.
Extends the Life of Your Bras
A well-fitting bra experiences less stretching, slipping, or wear and tear. That means your bras last longer and maintain their shape and elasticity over time. Investing a few minutes to find your correct bra size can actually help you save money in the long run.
Common Bra Fitting Mistakes
Even when using the correct bra size chart, many women still experience poor fit due to small measurement errors or old sizing habits. Knowing these common mistakes will help you achieve a more accurate, comfortable fit.
Wearing the Wrong Band Size
The band should sit firmly against your ribcage without digging in or riding up. A loose band gives little support, while a tight one causes discomfort and leaves marks. Always measure your underbust correctly and choose the closest band size listed in the bra size calculator.
Overflowing Cups or Gaping Gaps
Cups that are too small can cause bulging at the top or sides, while cups that are too large create wrinkles or empty spaces. Your breasts should be fully enclosed within the cups for a smooth, natural shape.
Ignoring Strap Position
Straps are there to keep your bra in place, not to carry the full weight of your bust. If your straps dig into your shoulders or keep slipping off, recheck your band and cup size using the bra size calculator. A proper fit ensures that most of the support comes from the band, not the straps.
Using Outdated Measurement Methods
Avoid the old "add four inches" rule, which was used decades ago when bras were made from non-stretch fabrics. Modern bras are elastic, so you should always use your exact under-bust measurement for accurate sizing.
Correcting these common fitting mistakes can make a big difference in both comfort and appearance. A well-fitted bra will feel secure, smooth under clothing, and supportive all day long.
International Bra Size Conversion Chart
The International Bra Size Conversion Chart helps you compare your bra size across different countries. Since every region uses its own sizing system, this table makes it easy to match your size in US, UK, EU, FR, JP, and AU measurements. It's a quick way to find your perfect fit when shopping for bras from international brands.
| US / UK Band Size | EU (EN 13402) | FR / BE / ES | JP (Japan) | AU / NZ |
|---|---|---|---|---|
| 28 | 60 | 75 | 55 | 6 |
| 30 | 65 | 80 | 60 | 8 |
| 32 | 70 | 85 | 65 | 10 |
| 34 | 75 | 90 | 70 | 12 |
| 36 | 80 | 95 | 75 | 14 |
| 38 | 85 | 100 | 80 | 16 |
| 40 | 90 | 105 | 85 | 18 |
| 42 | 95 | 110 | 90 | 20 |
| 44 | 100 | 115 | 95 | 22 |
| 46 | 105 | 120 | 100 | 24 |
| 48 | 110 | 125 | 105 | 26 |
| 50 | 115 | 130 | 110 | 28 |
International Cup Size Conversion Chart in inches and CM
The International Cup Size Conversion Chart helps you compare your cup size in different countries. Your cup size is based on the difference between your bust and band measurements. The tables below show how that difference changes your cup size in US, UK, EU, FR, JP, and AU sizing systems, first in inches and then in centimeters. These charts make it easier to understand what your measurements mean and to find the right fit when shopping for bras from anywhere in the world.
Bust and Band Difference Chart (In Inches)
| Difference (Bust – Band) | US / UK Cup Size | EU Cup Size | FR / ES Cup Size | JP (Japan) | AU / NZ Cup Size |
|---|---|---|---|---|---|
| Less than 1" | AA | AA | AA | AA | AA |
| 1" | A | A | A | A | A |
| 2" | B | B | B | B | B |
| 3" | C | C | C | C | C |
| 4" | D | D | D | D | D |
| 5" | DD / E | E | E | E | DD / E |
| 6" | DDD / F | F | F | F | F |
| 7" | G | G | G | G | G |
| 8" | H | H | H | H | H |
| 9" | I | I | I | I | I |
| 10" | J | J | J | J | J |
| 11" | K | K | K | K | K |
Bust and Band Difference Chart (In Centimeters)
| Difference (Bust – Band) | US / UK Cup Size | EU Cup Size | FR / ES Cup Size | JP (Japan) | AU / NZ Cup Size |
|---|---|---|---|---|---|
| 0–2 cm | AA | AA | AA | AA | AA |
| 2.5 cm | A | A | A | A | A |
| 5 cm | B | B | B | B | B |
| 7.5 cm | C | C | C | C | C |
| 10 cm | D | D | D | D | D |
| 12.5 cm | DD / E | E | E | E | DD / E |
| 15 cm | DDD / F | F | F | F | F |
| 17.5 cm | G | G | G | G | G |
| 20 cm | H | H | H | H | H |
| 22.5 cm | I | I | I | I | I |
| 25 cm | J | J | J | J | J |
| 27.5 cm | K | K | K | K | K |
Why Use Our Bra Size Calculator
Finding your correct bra size should be simple and stress-free. Our Bra Size Calculator provides quick, accurate results, making bra shopping easier and more reliable.
Fast and Accurate Results
Just enter your bust and band measurements, and the calculator will instantly show your correct size without any manual calculations.
Works for All Countries
Whether you shop from the United States, the United Kingdom, Europe, France, Japan, or Australia, the tool automatically converts your measurements to match international sizing standards.
Data Privacy Ensured
Your measurements are not stored or shared. Everything you enter stays private and secure.
Free and Mobile Friendly
The tool is free to use and works smoothly on mobile, tablet, and desktop devices without requiring downloads or registration.
Popular Bra Size Guides
Popular Bra Style Guides
Strapless Bra | Balconette Bra
Ready to Check Your Exact Size?
Use our Bra Size Calculator to find your perfect fit in seconds.
Frequently Asked Questions
What's the best way to measure bra size at home?
Use a soft measuring tape to measure your band size (around your ribcage, just under the bust) and bust size (around the fullest part of your chest). Subtract the band from the bust measurement to find your cup size or simply use our bra size calculator.
How often should I recheck my size?
It's best to remeasure every 6 to 12 months, or after any noticeable body changes such as weight gain, weight loss, or pregnancy.
Is my bra size the same in every brand?
No. Different brands may have slight variations in sizing. Always check the brand's size chart or try on bras to confirm your best fit.
What if I'm between two band sizes?
If you are between sizes, choose the larger band size for comfort and adjust the cup size down (for example, from 34C to 36B).
Can I calculate my bra size without a measuring tape?
While a measuring tape gives the most accurate results, you can use a string and ruler as an alternative. Wrap the string around your bust and band area, then measure its length with a ruler.
How to measure bra size in the UK and India?
Measuring your bra size in the UK and India is the same. Measure your band and bust size, then subtract the band from the bust to find your cup size. Both countries use the same sizing method and chart system.