The Perfect Bra Sizing Calculator UK | MissFine

Bra Size Calculator UK | MissFine
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Bra Size Calculator UK

Most women are in the wrong bra size, not because they haven't tried but because the measuring method most shops use adds inches it shouldn't. We stock 32A to 48FF.

Find Your Perfect Fit

Answer a few quick questions and we'll calculate your ideal bra size with international conversions, sister sizes, and personalised fit advice.

🔒 Private & Secure⏱ Takes 2 minutes🌐 All sizes worldwide

Choose your experience

Select one to get started

Find My Size
Measure and get your exact size with personalised recommendations
Check My Fit
Tell us how your bra feels — we'll work out the right size for you
Find My Style
Discover which bra styles suit your lifestyle best
Measurements
1

Take Your Measurements

You'll need a soft measuring tape. Stand naturally, breathe normally, bra off.

📏 How to measure:
1. Upper bust — Across the fullest part of your chest.
2. Under bust — Snugly around your ribcage below the breast.
cm
cm
Pro tip: Keep the tape parallel to the floor and firm — not tight. Measure twice for accuracy.
Step 1 of 5
1

What size are you wearing now?

We'll use this as our starting point.

Quick tip: Check the label inside your bra — size is on the back hook or side seam.
≈ UK size: —
Step 2 of 5
2

How does the band feel?

The band does 80% of the support work.

✓
Snug and comfortable all dayStays level, two fingers fit underneath
✓
↑
Rides up my backThe back rises higher than the front
✓
!
Too tightHard to breathe or feels constricting
✓
~
Digs in and leaves marksRed marks or indentations after wearing
✓
Step 3 of 5
3

How do the straps behave?

✓
Stay in place all dayNo sliding, no digging
✓
↓
Fall off my shouldersEven when tightened they slip
✓
!
Dig in even when loosenedPainful grooves in my shoulders
✓
~
Leave painful red marksDeep indentations by end of day
✓
Step 4 of 5
4

How do the cups fit?

✓
Smooth and fully containingNo gaps, no overflow, flat edges
✓
↑
I spill over the top or sidesBreast tissue escaping the cup
✓
○
Gaping or empty spaceCup doesn't make full contact
✓
≡
Double-bust effectCup edge cuts into breast tissue
✓
Step 5 of 5
5

What about the front panel?

The centre gore — the strip between the cups.

✓
Lies flat against my sternumSits flush with no gap or pressure
✓
↑
Lifts away from my chestFloats or gaps away from my body
✓
!
Digs into my breast tissuePainful where it presses in
✓
—
I wear wire-free brasNo centre gore to assess
✓
Step 1 of 5
1

When do you most need a bra?

Select all that apply.

☕
Everyday wear
✓
💼
Work & office
✓
🏃
Exercise & sport
✓
🌹
Evenings out
✓
🌙
Sleep & lounge
✓
✨
Special occasions
✓
Step 2 of 5
2

What's your style aesthetic?

🤍
Clean & minimalInvisible, seamless, no fuss
✓
🌸
Feminine & prettyLace, delicate details, soft colours
✓
⚡
Sporty & functionalPerformance over form
✓
🌹
Sensual & confidentLingerie that makes me feel stunning
✓
Step 3 of 5
3

How do you feel about underwire?

💪
I love itGives me the shape and lift I want
✓
🙅
I avoid itComfort always comes first
✓
🤷
Depends on the occasionI wear both
✓
Step 4 of 5
4

What coverage do you prefer?

🛡
Full coverageCompletely contained, maximum modesty
✓
👌
MediumGood support without being restrictive
✓
💋
Low-cut plungeI like a flattering neckline
✓
Step 5 of 5
5

What matters most in a bra?

👻
Invisible under clothes
✓
😌
All-day comfort
✓
✨
Flattering shape
✓
💪
Maximum support
✓
Your MissFine Size
—
UK · Primary Size
🇺🇸 US—
🇪🇺 EU—
🇫🇷 FR/ES—
🇦🇺 AU—

Fitting Tips for You

Free UK delivery · 30-day returns · Sizes 32A to 48FF

Shop My Size on MissFine →
✓
—
—

What to Change & Why

Ready to find a bra that genuinely fits?

Shop MissFine →
Your Style Profile
—
—
Your Perfect Match
Also Worth Trying

Sizes 32A to 48FF · Free UK delivery · 30-day returns

Explore MissFine →

Why the right fit changes everything

80%of women wear the wrong bra size without realising it
6+size changes the average woman goes through in her lifetime
2 minis all it takes to find your perfect fit with our calculator

A well-fitting bra improves posture, reduces back and shoulder pain, and changes how you feel wearing clothes.

🌐

International Sizing

UK, US, EU/FR, and AU/NZ systems.

↔

Sister Sizes

Equivalent sizes across band widths.

🔍

Fit Diagnostics

Diagnose and fix common fit issues.

✨

Style Matching

Personalised style recommendations.

Not sure where to start?

Pick any path above. Our calculator guides you through every step.

How to measure your bra size at home

Follow these easy steps using a soft measuring tape. For the most accurate result, wear a non-padded bra or nothing at all.

Band measurement (band size): Wrap the measuring tape snugly around your torso at the level of your rib cage, directly below your breast tissue where your ribs meet your breasts, parallel to the floor. Make sure the tape is not slipping down at the back. Round to the nearest even number. That is your band size. If you measure 31 inches, your band is 32. If you measure 33 inches, your band is 34.

Bust size (cup size): Wrap the tape loosely around the fullest part of your bust, straight and parallel to the floor. Do not pull tight. The inch difference between your bust size and band measurement gives your cup size: 1 inch = A, 2 = B, 3 = C, 4 = D, 5 = E, 6 = F, 7 = FF. For example, a 32-inch band and a 35-inch bust gives a 32C. Note: US sizing calls 5 inches DD. In UK sizing this is E. MissFine uses UK sizing throughout.

Do not add inches to your underbust. Adding 4 or 5 inches is an outdated method from when bra fabrics had almost no stretch. Your actual underbust measurement is your band size.

Once you have put on your bra, lean forward and use your hands to gently scoop all breast tissue fully into the cups before standing upright. This is the Swoop and Scoop method and ensures correct positioning, especially for underwired styles. It is worth checking your measurements every 12 to 18 months, as weight, hormonal changes, and ageing all affect bra size over time.

Six signs your bra doesn't fit

The band rides up at the back
The band should sit snug on your ribs and stay level across your torso. If it rides up, the bra is too loose. A riding band causes the breasts to drop, leading to spillage and back aches. The band does 80% of the support work. If it is not level, it is not working.
The straps dig in or slide off
Straps should not be the main source of support. If they are digging into your shoulders, your underband is too loose and the straps are compensating. If the straps slide or drop, the band is likely too big. Red marks on your shoulders that last more than an hour mean you need to drop a band size.
The cups gap or overflow
Gaping means the cup is too big or the wrong shape for your breast shape. If breast tissue is spilling out at the top or sides, the cup is too small. Both are fit problems, not body problems.
The underwire sits on breast tissue
The underwires should sit flat against your chest wall with no breast tissue between the underwire and your ribs. The centre front should sit flat against the chest bone. If the centre front lifts away, the cup is too small. This applies to everyday bras and sports bras.
There is a groove in your shoulder
Deep red marks or grooves that last after removing the bra mean straps are carrying weight the band should be carrying. Drop a band size.
You adjust it more than twice a day
A well-fitting bra stays put. Constantly repositioning the cups, pulling the band down, or pushing the straps up is a sign your current bra size is not right. That is worth checking.

UK bra size conversion chart

UK US EU FR/ES AU
32A 32A 70A 85A 10A
34B 34B 75B 90B 12B
36C 36C 80C 95C 14C
36D 36D 80D 95D 14D
36E 36DD 80E 95E 14E
36F 36DDD/F 80F 95F 14F
38FF 38G 85FF 100FF 16FF
40G 40H 90G 105G 18G

UK cup sizing runs: A, B, C, D, E, F, FF, G, GG, H, HH, J, JJ. There is no DD label in UK sizing. What US shoppers know as DD is E in UK sizing. Bra sizes can vary between brands, so always use your measurements rather than a label from a previous purchase. If you are trying bras in a fitting room, test your calculated size alongside one cup size up and one down.

Frequently asked questions

What bra size am I?
Enter your underbust and bust measurements into the bra size calculator above. You will get your UK size, US equivalent, EU, FR/ES and AU conversions, and your sister size options.
How do I measure my bra size at home?
Use a measuring tape and two measurements: underbust for band size and bust size for cup size. Wear a non-padded bra or nothing. Do not add inches to your underbust. That is an outdated method. Each inch of difference corresponds to one cup size: 1 inch = A, 2 = B, 3 = C, and so on.
What is the difference between UK and US bra sizes?
UK and US band sizes are identical. The difference is in cup letters above a D cup. A UK E cup equals a US DD cup. A UK F cup equals a US DDD or F cup. The UK system uses double letters (FF, GG, HH) for larger cup sizes.
What is a sister size in bras?
Sister sizes share the same cup volume but have different band sizes. A 36C, 34D and 38B are all sister sizes with the same cup volume. If you drop a band size, go up a cup size to maintain the same cup volume. If you go up a band, drop a cup size.
Does MissFine use DD sizing?
No. MissFine uses UK sizing throughout. The cup sequence is A, B, C, D, E, F, FF — there is no DD label. If you are used to US sizing, your US DD is a UK E and your US DDD or F is a UK F.
What sizes does MissFine stock?
MissFine stocks bras from 32A to 48FF including 40 front-opening styles and sports bras across the full size range. All sizes use UK cup labelling with no DD label.
Why should I not add 4 inches to my underbust measurement?
The old plus-4-inch method was developed when bra fabrics had almost no stretch. Today's bras use elastic fabrics. Adding 4 inches gives a band that is too large to provide proper support. Your actual underbust measurement, rounded to the nearest even number, is your band size.
How do I know if my bra fits correctly?
A bra that fits should feel like a second skin — supportive but barely noticeable. The band sits level on your ribs. Two fingers slide flat underneath. Straps stay in place without digging in. Cups fully contain your breast tissue. The underwires sit flat against your chest wall. The centre front sits flat against your sternum. Always fasten on the loosest hooks when the bra is new.
What is the difference between cup size and band size?
The band size (the number) is the circumference of your ribcage below your bust. The cup size (the letter) is the difference between your bust and underbust measurements. It is not an absolute size. A 32D and a 38D are completely different sizes.
How often should I remeasure my bra size?
Accurate measurements change over time due to weight fluctuations, hormonal changes, and ageing. Remeasure every 12 to 18 months as a routine check, and after any significant weight change, pregnancy, or breastfeeding period. If your bra suddenly feels different (band riding up, cups gaping), remeasure before buying new bras.
What is the Swoop and Scoop method?
After putting on your bra, lean forward and scoop all breast tissue fully into the cups before standing upright. This positions your breasts correctly and gives you the full support the bra is designed to provide, especially for underwired styles and sports bras.

Need help finding your size?

Email us at info@missfine.co.uk. Thirteen years of bra fitting expertise and happy to help before you order.

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