Bra Size Calculator: Find Your Perfect Fit with Accurate, Easy Measurements
Finding the perfect bra size can be confusing, especially with different sizing systems like U.S. and UK. Our free online Bra Size Calculator makes it easy to determine your exact fit in seconds—just enter your band and bust measurements in inches, and get your accurate bra size instantly.
Whether you’re shopping for everyday bras, sports bras, or lingerie, knowing your correct size helps avoid discomfort, gaping cups, or tight straps. This tool works for both U.S. and UK bra size conversions, so you never have to guess again. Ideal for women who shop online and want a fast, accurate bra size calculator that gives instant results.
Learn your sister sizes too, so you always have backup options. Say goodbye to poor-fitting bras and hello to all-day support and confidence. Perfect for women in the USA, UK, or worldwide looking for bra sizing help, bra measurement guide, or how to calculate bra size at home—accurately and easily!
Bra Size Measurement Guide (With Visual Help!)
Step 1: Measure Your Band Size**
(The snug measurement under your bust)
- Wrap the tape around your ribcage, right under your breast crease
- Keep it level – parallel to the floor (use a mirror to check)
- Snug but comfortable – exhale normally, don’t squeeze too tight
- Note the number in inches or centimeters
Step 2: Measure Your Bust Size**
(The fullest part of your chest)
- Wear a non-padded bra or no bra
- Wrap the tape around the fullest part (usually nipple level)
- Keep tape loose – just touching skin without compressing
- Note the number in same units as band size
Step 3: Calculate Your Size**
- Subtract band from bust
(Example: 38″ bust – 34″ band = 4″ difference) - Use our calculator with these numbers
- Get your perfect size in:
- US (DD, DDD)
- UK (DD, E, F)
- EU (cm sizing)
Calculate Bra Size
International Bra Cup Size Conversion Chart
| Cup Difference (Bust – Band) | US | UK | EU | FR | AU | JP |
|---|---|---|---|---|---|---|
| 1 inch | A | A | A | A | A | A |
| 2 inches | B | B | B | B | B | B |
| 3 inches | C | C | C | C | C | C |
| 4 inches | D | D | D | D | D | D |
| 5 inches | DD (E) | DD | E | E | DD | E |
| 6 inches | DDD (F) | E | F | F | E | F |
| 7 inches | G | F | G | G | F | G |
| 8 inches | H | FF | H | H | FF | H |
| 9 inches | I | G | I | I | G | I |
| 10 inches | J | GG | J | J | GG | J |
| 11 inches | K | H | K | K | H | K |
Bra Size Calculator – Frequently Asked Questions (FAQ)
How do I calculate my bra size at home?
To calculate your bra size at home, measure your band size (underbust) and bust size (overbust) in inches. Subtract the band size from the bust size to determine the cup size. Use a bra size calculator to convert your measurements into U.S. and UK sizing.
How do I measure my bra size using this calculator?
Using our bra size calculator is simple. Measure snugly under your bust for your band size, and measure around the fullest part of your bust for your cup size. Enter these two numbers into the calculator, and it will suggest your best bra size.
How do you find the range on a calculator?
The “range” here means the range of sizes our calculator supports — from small to large band and cup sizes — to help every body type find a fit.
What is the biggest number a calculator can handle?
Our calculator isn’t about big numbers — it’s designed to work within the full range of realistic bra sizes, not extreme mathematical calculations.
How do you calculate sample size?
For bras, “sample size” isn’t relevant. You just need your underbust and bust measurements for an accurate fit.
Are bra size calculators accurate?
Bra size calculators are a great starting point. While they provide accurate recommendations based on your measurements, comfort can vary by brand and style.
Can I use both inches and centimeters?
Yes! Our calculator allows you to choose between inches and centimeters to suit your preference.
How accurate is the bra size calculator?
Our calculator follows industry-standard formulas to give you a reliable starting point. Final comfort always depends on how the bra fits on your body.
Why is there a difference in bra sizes across brands?
Each brand has its own fit and style, which can cause sizing to vary slightly. Always check the brand’s size chart for the most accurate fit.
What is the range of sizes supported by this calculator?
We support a wide range of band and cup sizes to help everyone, from petite to plus-size, find their ideal fit.
Why does my bust size dropdown change when I select a different band size?
Changing your band size affects your cup size because of “sister sizing.” Our calculator adjusts the dropdown options to ensure you get a balanced, accurate result.
What brands are supported by the calculator?
Our calculator uses standard sizing methods that work with most major bra brands. Still, it’s smart to check specific brand charts for accuracy.
Can this calculator help me find my bra size in different countries?
Yes! We include conversions for US, UK, EU, and other sizing systems to make international shopping easier.
Does the calculator work for all bra types?
Our calculator works well for everyday bras, sports bras, maternity bras, and more. Keep in mind that specialty bras may fit slightly differently.
Is there a way to save my results for future use?
Currently, we recommend writing your size down or bookmarking your result for easy reference later.
How is your bra size calculator different from ‘a bra that fits calculator’?
Ours is designed to be quick, simple, and easy to use without overwhelming options. Perfect for fast, reliable results.
Why is using a brand-specific chart important for calculating bra size?
Brand-specific charts fine-tune your size because each brand may follow slightly different sizing standards. Our calculator provides a strong starting point.
Can I use your calculator to find my size for any brand?
Yes. Our calculator helps you find your general size, but we always recommend double-checking with a brand’s own chart for perfect accuracy.
Is your bra size calculator suitable for international brands?
Yes! We convert between international sizing systems to help you confidently shop from brands around the world.
How does your calculator improve on traditional bra measurement methods?
Our calculator removes the guesswork by using proven measurement formulas for quick and accurate results — no confusing steps or guesswork needed.