Bra Size Chart
Find your band from your underbust, your cup from the bust-band difference, and convert any size between US, UK, EU, FR & AU.
How to read a bra size chart
A bra size chart maps two measurements to a size. Your band comes from your underbust (snug, rounded to the nearest even number). Your cup comes from the difference between your bust and band — one inch per cup (1″ = A, 2″ = B, 3″ = C, 4″ = D, then DD and beyond).
Read the chart in two steps: first look up your band from your underbust measurement, then look up your cup from the bust-band difference. Together they give your full size, which you can then convert to any region below. Prefer to skip the lookup? The calculator does both steps from your numbers in one go.
Measure your underbust snug and level, round to the nearest even number. That's your band (e.g. 34).
Measure your bust loosely, subtract the band. Each inch of difference is one cup (3″ → C).
Take your size (e.g. 34C) to the conversion table to read it in UK, EU, FR or AU.
Band size chart (from underbust)
Measure snugly around your ribcage, directly under the bust, and round to the nearest even number.
| Underbust (in) | Underbust (cm) | Band |
|---|---|---|
| 27–28″ | 69–71 cm | 28 |
| 29–30″ | 74–76 cm | 30 |
| 31–32″ | 79–81 cm | 32 |
| 33–34″ | 84–86 cm | 34 |
| 35–36″ | 89–91 cm | 36 |
| 37–38″ | 94–96 cm | 38 |
| 39–40″ | 99–101 cm | 40 |
| 41–42″ | 104–106 cm | 42 |
| 43–44″ | 109–111 cm | 44 |
Cup size chart (from the difference)
Subtract your band from your bust measurement. Each inch of difference is one cup size. Cup letters are identical in the US and UK up to a D; above D they diverge.
| Bust − band | US cup | UK cup | EU cup |
|---|---|---|---|
| < 1″ | AA | AA | AA |
| 1″ | A | A | A |
| 2″ | B | B | B |
| 3″ | C | C | C |
| 4″ | D | D | D |
| 5″ | DD | DD | E |
| 6″ | DDD | E | F |
| 7″ | G | FF | G |
| 8″ | H | G | H |
Above a D cup, US sizing doubles letters (DD, DDD) before moving to G, H; the UK continues the alphabet (DD, E, F, FF, G); and the EU uses a single run (E, F, G, H). This is the main source of confusion when shopping across regions.
Full bra size chart (bust measurements)
Find your band down the left and your cup across the top — the cell shows the approximate bust measurement in inches for that size. Linked sizes have a full guide.
| Band \ Cup | A | B | C | D | DD | DDD |
|---|---|---|---|---|---|---|
| 30 | 31 | 32 | 33 | 34 | 35 | 36 |
| 32 | 33 | 34 | 35 | 36 | 37 | 38 |
| 34 | 35 | 36 | 37 | 38 | 39 | 40 |
| 36 | 37 | 38 | 39 | 40 | 41 | 42 |
| 38 | 39 | 40 | 41 | 42 | 43 | 44 |
| 40 | 41 | 42 | 43 | 44 | 45 | 46 |
Bust figures are centre-of-range. The band number itself comes from the underbust, not the bust. Rows are even bands; odd measurements round to the nearest even band.
International size conversion chart
Band numbers and cup letters differ by region. Use this to convert any US size to UK, EU, FR or AU.
| US / UK | EU | FR / ES | AU |
|---|---|---|---|
| 30 | 65 | 80 | 8 |
| 32 | 70 | 85 | 10 |
| 34 | 75 | 90 | 12 |
| 36 | 80 | 95 | 14 |
| 38 | 85 | 100 | 16 |
| 40 | 90 | 105 | 18 |
| US | UK | EU / FR |
|---|---|---|
| A | A | A |
| B | B | B |
| C | C | C |
| D | D | D |
| DD | DD | E |
| DDD | E | F |
| G | FF | G |
Skip the lookup
Enter two measurements and get your exact size across all five systems — plus your sister sizes — in under 30 seconds.
Calculate My Bra Size →Bra size chart — answered
How to read a sizing chart, convert between regions, and reconcile it with real-world brand fit.
How do I read a bra size chart?
A bra size chart maps your underbust to a band and your bust-band difference to a cup, then lets you convert that size between regions.
The two steps
First find your band: measure your underbust snugly and level, then round to the nearest even number. Next find your cup: subtract that band from your bust measurement and count one cup for each inch of difference — 1″ is an A, 2″ a B, 3″ a C, and so on.
Putting it together
Combine the two — a 34 band with a 3″ difference is a 34C — then take that full size to the conversion table to read it in UK, EU, FR or AU.
Band comes from the underbust; cup comes from the bust-minus-band difference. Read them together.
What is the difference between a bra size chart and a calculator?
A bra size chart is a fixed reference table you read by hand; a calculator computes your personalized size from your measurements and converts it automatically.
How each works
A chart shows ranges, so you locate the row and column that match your numbers. A calculator takes your exact underbust and bust, applies the rounding and difference rules for you, and returns your band, cup, sister sizes and conversions in one step.
When to use which
Reach for the calculator to get your starting size quickly, and the chart to see the wider picture — neighbouring sizes, regional equivalents, and how a measurement shifts the result.
Use the calculator to get your size, the chart to understand and convert it.
Are bra size charts the same in every country?
No. Band numbers and cup letters follow different conventions by region, so the same body maps to a different label in the US, UK, EU, FR and AU.
Where they agree
The US and UK share the same band numbers and use the same cup letters up to a D, so a 34C is a 34C in both. That overlap is why US/UK charts look almost identical.
Where they diverge
The EU and France use centimetre-based bands — EU is the US band × 2.5 − 10, and FR adds 15 to the EU number — while Australia runs on its own scale (US band − 22). Cup letters also split above a D: the US doubles to DD and DDD, the UK continues DD, E, F, FF, and the EU uses a single run E, F, G.
Always convert deliberately when using a chart from another region — especially above a D cup.
Why doesn't my measured size match the brand's chart?
Because there is no enforced universal sizing standard — each brand drafts its own cups, wires and band stretch, so a measured size is a starting point, not a guarantee.
Why brands differ
Two labels can cut a “34C” differently: one runs shallow, another deep; one band stretches more than another. The result is that a measured 34C can fit like a 34B in one brand and a 34D in another.
What to do about it
Treat the chart as your anchor, then adjust by feel. If the cups fit but the band is off, move to a sister size; if a brand is known to run small or large, shift accordingly and read its own fit notes.
A chart gives your starting size; final fit comes from trying it on and adjusting with sister sizes.