Women's Underwear Size Chart & Panty Size Calculator
Two measurements, waist and hips. Your US alpha and numeric size, the UK, EU and Australian equivalents, and why the same size fits differently in a brief and a thong.
What size underwear am I, in two sentences Measure around the fullest part of your hips and around your natural waist. Match the hip measurement to the chart below; panties sit on the hips, so when waist and hips disagree, the hips decide. A 38″ hip and a 28″ waist is a US medium, size 8 to 10.
Not sure where the tape goes? See the two steps below
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How to measure for underwear
Two numbers, taken in a minute with a soft tape over bare skin or thin underwear. Hips set the size; waist tells you which styles will sit where you want them.
Measure the fullest part of your hips
Stand with your feet together. Wrap the tape around the widest point of your hips and seat, usually seven to nine inches below your natural waist, and keep it level all the way around. Snug, not tight: the tape should sit on the body without pressing in. This is the measurement almost every panty chart is graded on, because the leg openings and the seat are cut to it.
Measure your natural waist
Bend to one side; the crease that forms is your natural waist, typically an inch or two above the navel and higher than where jeans sit. Stand straight, wrap the tape level around that point and read it while breathing normally. Do not pull in. High-waist briefs and control styles are cut to this number; low-rise styles never reach it.
Soft tape, or a substitute
Fabric or vinyl. No tape? A ribbon or shoelace marked and laid against a ruler is close enough.
Bare skin or thin underwear
Never over jeans, leggings or shapewear, which add an inch and a size.
Feet together
Standing with feet apart flattens the seat and under-reads the hips.
Between sizes? Go up
Elastic that is slightly loose disappears. Elastic that is slightly tight digs in and shows through clothes.
Women's underwear size chart
Hip and waist measurements in inches and centimeters against every label you will meet: US alpha, US numeric (dress size), the panty number printed by mass-market brands, and the UK, EU and Australian equivalents. The row matching the calculator is marked.
| US alpha | Hips | Waist | US numeric | Panty number | UK | EU | AU / NZ |
|---|
Hips are the primary column; waist ranges are typical for that hip size, not a second rule. The panty number (4 to 10) is the system Hanes, Bali, Fruit of the Loom and most department-store brands print, and it tracks the alpha size one-to-one. Designer and European brands use the alpha or the dress size instead. Ranges overlap at the edges by design: a 37″ hip is the top of a small and the bottom of a medium, and which one fits depends on the style, covered below.
Underwear size conversion: US, UK, EU and Australia
Panty sizing diverges across countries the way bra sizing does, but with fewer rules. Three moves cover it: the UK number is the US number plus four, the European number is the UK number plus 28, and Australia uses the UK number. Alpha sizes are the same letters everywhere but are not pinned to the same numbers, which is where most cross-border orders go wrong.
| US | UK | EU / DE / NL | AU / NZ | Usual alpha |
|---|
A US 6 is a UK 10, an EU 38 and an AU 10: one body, four labels. French and Italian brands mostly print EU numbers or the alpha; Japanese brands print the alpha with cuts graded a size smaller than Western brands, so size up one letter on a first order. The "usual alpha" column is the most common mapping; a brand that calls a US 4 a small and a brand that calls it an extra small are both following a real convention, which is why the measurement, not the letter, is what to convert.
UK and Australian labels
Both use the same even numbers, four higher than the US. A UK or AU 12 is a US 8. British and Australian brands often print the alpha as well, mapped S to 8–10 and M to 12–14 in their own numbers, which is the same body as a US S 4–6 and M 8–10.
European labels
Continental sizes run 32 to 56 in twos, 28 above the UK number. An EU 40 is a UK 12 and a US 8. Some European lingerie brands skip the numbers and print the alpha, or print both; if a tag reads 40 / M, that is one size shown two ways.
Why the same size fits differently by style
A brief and a thong labeled medium are cut to the same hip measurement, and they still fit differently, because coverage decides where the garment sits and where its elastic lands on your body. Size charts present size as absolute. It is a starting point that each style adjusts.
Full brief
Sits at the natural waist · full seatThe waistband lands on the waist measurement and the leg elastic wraps the full seat, so both numbers matter. If your waist is a size larger than your hips, briefs are the style where you follow the waist. Fits truest to the chart of any style.
Hipster and boyshort
Sits below the waist · wide legThe waistband rests on the top of the hips, well below the natural waist, so the waist measurement barely applies. The wide leg opening spreads pressure and is forgiving on the seat. Size to the hips; between sizes, most people size down here without digging.
Bikini
Sits mid-hip · moderate seatSits partway down the hip with a higher-cut leg. The leg elastic crosses the seat diagonally and is the first place a bikini that is too small shows. Size to the hips and take the larger size if you are between; the waistband has less to hold onto than a brief's.
Thong and G-string
Sits at low to mid hip · minimal backAlmost nothing crosses the seat, so the hip number controls only the waistband and the front. This is why one-size thongs work across a range of bodies and why a thong in your chart size can feel loose: there is less fabric to fill. Size down before sizing up if the waistband shifts.
High-waist and control
Sits above the navel · firm fabricCut to the natural waist with power-mesh or firm knit that has less give than lace or cotton. Follow the waist measurement, and if you are between sizes, go up: a control brief that is too small rolls at the waistband instead of smoothing.
Seamless and laser-cut
Bonded edges · no elasticNo elastic means nothing to grip, so these rely on fabric tension. They run true to the hips but feel smaller than lace at the same size. Size up if you prefer them to disappear rather than hold.
Fabric changes the answer too. Stretch lace and modal give an inch; cotton and microfiber give less; bonded and power-mesh give the least. The same medium in three fabrics is three slightly different sizes. The women's underwear guide walks through every style, its rise, and who it suits.
Why brands disagree, and how far
There is no standards body for underwear sizing. Each brand grades to its own fit model and its own idea of a medium, so the chart above is a starting point and the brand's own chart always wins. These are the patterns worth knowing before you order.
| Brand or type | Sizes printed | What to know |
|---|---|---|
| Hanky Panky | One size, plus, and XS–XL | The original-rise thong is one size for US 4 to 14, hips about 36 to 45 inches, because a stretch-lace thong has almost no seat to fit. The low rise fits 2 to 12, petite 0 to 4, plus 14 to 24 (hips 44 to 57). Sized styles run XS 0–2, S 4–6, M 8–10, L 12–14. One size is not one fit: if you are at the edge of the range, the plus or petite version is the better thong. |
| Cosabella, Natori, Fleur du Mal | XS–XL, some to 3X | Designer lingerie graded on the dress-size mapping: S 4–6, M 8–10, L 12–14. Stretch lace and modal give an inch, so these fit true to the chart or slightly generous. Italian-made lace can run a touch small in the leg on fuller seats; size to the hips. |
| Wacoal, Chantelle, Simone Pérèle | XS–3X; EU numbers on some | Graded to match their bras, which means a firmer, more structured fit than a pure lace brand. Chantelle and Simone Pérèle print the EU number on European stock and the alpha in the US; a 40 and an M on the same tag are one size. |
| Hanes, Bali, Fruit of the Loom, Maidenform | Panty numbers 5–10, with alpha | Mass-market brands print the panty number: 5 is small, 6 medium, 7 large, 8 XL, 9 2X, 10 3X, graded about two inches of hip per number. Cotton and nylon with little stretch, so the chart is the fit; there is no give to size down into. |
| Commando and other seamless | XS–XL | Laser-cut microfiber with bonded edges relies on fabric tension. Runs true to the hips but feels a size smaller than lace. Size up if you want it to vanish rather than hold. |
| Fast fashion and marketplace brands | Alpha, often compressed | Alpha sizes that map to smaller numbers than the chart here, so a labeled M may be a US 6. Measurements beat the letter. Read the brand's centimeter chart, and if there is not one, order two sizes and return one. |
Brand notes are general tendencies from published size charts and fit patterns, not guarantees. Every product page on HauteFlair shows the brand's own size chart beside the size selector.
Six signs your underwear is the wrong size, or the wrong style
The chart gives you the size. The pair you try on tells you whether the size or the cut needs to change. Match the symptom, apply the fix, and re-run the calculator if you need to.
Women's underwear sizes, answered
What size underwear am I?
How do I measure for underwear?
Should I size underwear by waist or hips?
What is a size 7 in panties?
What is a medium in women's underwear?
How do US underwear sizes convert to UK, EU and Australian sizes?
Why does a thong fit differently from a brief in the same size?
What does one size fit in Hanky Panky?
What if I am between two sizes?
Is my underwear size the same as my jeans size?
Do plus sizes follow the same chart?
How often should I re-measure?
How this calculator works
No proprietary table. One lookup on the hips, one check against the waist, published here so you can test it against a pair you own.
What we deliberately do not do
No brand fudge. Where a brand runs small or large we say so in words, on this page and on the product page, rather than shifting the chart.
No single letter for everything. The result shows alpha, numeric and panty number because the tag you are buying only prints one.
No stored measurements. Your two numbers are remembered in your own browser so the page opens where you left it. Nothing is sent anywhere.
Conversions were checked against published brand and retailer charts (ASOS, Hanes, Hanky Panky) in September 2026. Bra sizing lives on the bra size calculator; this page covers the other half of the set.
Shop it in the style that sits where you want
Briefs, bikinis, thongs, boyshorts and high-waist, XS to 3X, with free US shipping over $50.
Sizing reviewed against published US, UK and EU brand charts. Measurements never leave your browser.