A Bra That Fits Calculator for Your Accurate Starting Bra Size
Measure your ribcage three ways and your bust three ways. The calculator returns a starting size across eight international sizing systems, plus a nearby sister size when useful.
Start with six measurementsHow to Measure for the A Bra That Fits Calculator at Home
Use a soft tape directly against the body without a bra. Keep the underbust tape level, and let it follow the fullest breast circumference without pressing tissue down.
Before You Measure for an Accurate Bra Size Calculator Result
Use a flexible, non-stretch tape and check the back in a mirror, or ask someone you trust to help. Keep the same unit for every measurement and write down each value before changing position.
- Loose underbust with the tape just resting.
- Snug underbust at a comfortable band tension.
- Tight underbust fully exhaled and pulled firmly.
- Standing, leaning and lying bust around the fullest point.
Free Bra Fit Tools for Choosing the Right Size, Shape and Style
A size label cannot describe every fit variable. Use these practical tools to measure consistently, isolate a fit problem, compare bra constructions and understand unfamiliar terminology before shopping.
Bra Fit Troubleshooter
Select what feels wrong at the band, cups, straps or wires and get an ordered set of fit checks.
Open tool Compare constructionsBra Style Finder
Match support needs, shape characteristics and clothing plans with useful bra constructions to try.
Open tool Understand the termsBra Fit Glossary
Search the language used for sizing, breast roots, cup construction and common fit problems.
Open tool Prepare your numbersHow to Measure Bra Size
Follow the complete loose, snug, tight, standing, leaning and lying measurement guide.
Open toolWhy This Six-Measurement Bra Size Calculator Is Different
A single overbust measurement can miss how breast tissue shifts forward or outward. Standing, leaning and lying values give the cup calculation more context, while three underbust values show both ribcage circumference and compressibility.
The result is still a starting point. Bra shape, wire width, cup depth, fabric stretch and brand grading determine whether a particular style actually fits.
Read the complete bra size calculator methodologyInternational Bra Size Conversion Charts by Region for Europe, North America and Asia-Pacific
Compare one region at a time instead of scanning a single extra-wide global table. These labels are shopping references, not universal standards, so confirm the individual brand chart before ordering.
European Bra Size Conversion Chart for UK, EU, France, Spain and Italy
Use the UK band as a reference for common standard EU, French, Spanish, Belgian and Italian retail labels.
| UK | EU | FR / ES / BE | Italy |
|---|---|---|---|
| 28 | 60 | 75 | 00* |
| 30 | 65 | 80 | 0 |
| 32 | 70 | 85 | 1 |
| 34 | 75 | 90 | 2 |
| 36 | 80 | 95 | 3 |
| 38 | 85 | 100 | 4 |
| 40 | 90 | 105 | 5 |
| 42 | 95 | 110 | 6 |
| 44 | 100 | 115 | 7 |
| 46 | 105 | 120 | 8 |
| 48 | 110 | 125 | 9 |
| 50 | 115 | 130 | 10 |
Italian 00 at UK 28 is an extrapolated, less consistent label; many Italian brand charts begin at 0 / UK 30.
US and Canadian Bra Size Chart Compared with UK Cup Sizes
UK and US/Canadian band numbers commonly match, but cup lettering separates above D and varies between North American brands.
| Cup step | UK | US / Canada |
|---|---|---|
| 1 | A | A |
| 2 | B | B |
| 3 | C | C |
| 4 | D | D |
| 5 | DD | DD |
| 6 | E | DDD |
| 7 | F | G |
| 8 | FF | H |
| 9 | G | I |
| 10 | GG | J |
| 11 | H | K |
| 12 | HH | L |
| 13 | J | M |
| 14 | JJ | N |
US brands may use DD, DDD, F or other sequences differently. Confirm the exact brand chart before ordering.
Asian and Oceania Bra Band Size Chart for Japan, Australia and New Zealand
Japanese bras commonly use metric band labels, while Australia and New Zealand use local band numbers with UK-style cups.
| UK reference | Japan | Australia / NZ |
|---|---|---|
| 28 | 60 | 6* |
| 30 | 65 | 8 |
| 32 | 70 | 10 |
| 34 | 75 | 12 |
| 36 | 80 | 14 |
| 38 | 85 | 16 |
| 40 | 90 | 18 |
| 42 | 95 | 20 |
| 44 | 100 | 22 |
| 46 | 105 | 24 |
| 48 | 110 | 26 |
| 50 | 115 | 28 |
Japan 60 and Australia/New Zealand 6 are not stocked by every brand; availability and grading vary.
How to Know If a Bra Fits Correctly After Using a Bra Size Calculator
Start with the band, then assess the cups and wires after scooping all breast tissue into the cups. A calculated size is a starting point; comfort and stable support decide whether a specific bra fits.
| Area | Signs of a good fit | Warning signs | What to try next |
|---|---|---|---|
| Band | Level from front to back and comfortably firm on the loosest hook. | Rides up, shifts easily, or feels painfully tight by itself. | Test it backward and upside down. Then try a sister size up or down if needed. |
| Cups | Breast tissue is contained without spilling, cutting in, or empty space. | Bulging at the neckline or sides, wrinkling, or persistent gaps. | Scoop and swoop first, then change cup volume or try a different cup shape. |
| Center gore | Sits flat and feels stable between the breasts in a wired bra. | Floats away, twists, or presses painfully into the sternum. | Try more cup depth or volume; a lower gore may suit close-set breasts. |
| Underwires | Follow the breast root and rest behind all breast tissue at the sides. | Sit on tissue, slide below the root, or extend far beyond it. | Compare wider or narrower wires and shallower or deeper cup shapes. |
| Straps | Stay in place with light tension without carrying most of the support. | Dig in, fall down after adjustment, or must be overtightened. | Check the band and cups first, then adjust strap length and placement. |
Change one variable at a time. If the band feels stable but the cups do not, keep the band size and compare cup volumes or cup shapes before changing both numbers.
More Free Bra Size Calculators and Bra Fit Tools
A Bra That Fits Calculator FAQ for Better Bra Sizing
Use the result as the first size to try, then evaluate the band, cups and wires as separate fit checks.
How accurate is the A Bra That Fits calculator?
It is designed to give a strong starting size from six measurements. It cannot account for every breast shape, bra construction, brand grading choice or comfort preference, so nearby sizes should still be tried when possible.
Why does this bra size calculator use six measurements?
Three underbust measurements show ribcage size and compressibility. Standing, leaning and lying bust measurements capture tissue that can distribute differently in one upright measurement.
Should I use the bra size calculator in inches or centimeters?
Use the unit shown most clearly on your tape. The calculator normalizes centimeters and inches before applying the same method, so either entry mode can produce the same physical starting size.
What does a result such as 28F/FF mean?
It means both adjacent cup sizes are reasonable starting points in the selected sizing system. Cup letters are tied to band size, so 28F does not have the same cup volume as 34F.
Why is my calculated bra size different from the size I wear?
Many size charts add four inches to the underbust or fit into a limited product range. This method starts closer to the measured ribcage and may return a smaller band with a larger cup letter.
Does the calculator store my body measurements?
No. Calculation happens in the browser. The site does not submit or save the six measurements as a calculation history.