By Mohit Patel, Marketing Specialist, Tailor Size Guide
What Number Size Is a Medium? Women's, Men's and Kids'
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Add Tailor Size Guide as a preferred source on GoogleIn most US women's clothing, a Medium is a size 8 to 10, for a bust of about 36 to 38 inches. In men's clothing, a Medium fits a chest of about 38 to 40 inches and a waist of about 32 to 34 inches, with a 15 to 15½ inch collar. In US kids' clothing, a Medium usually means size 7 to 8.
Those are typical ranges, not rules. Every brand sets its own chart, European and Asian brands size differently, and "vanity sizing" has shifted numbers over the years. So use the tables below as a starting point, and check the brand's own measurements before you order. I'll also show you how a Medium converts to UK, EU and Asian sizes, and why the "average" body isn't actually a Medium any more.
Key takeaways
- Women's Medium ≈ US 8 to 10 (bust about 36 to 38 in). UK 12 to 14, EU 40 to 42.
- Men's Medium ≈ chest 38 to 40 in, waist 32 to 34 in, collar 15 to 15½ in.
- Kids' Medium usually = size 7 to 8; go by height, not age.
- Asian brands' Medium often fits like a US Small.
- Letter sizes vary by brand. Compare your measurements with the brand's chart.
Women's Medium: what number size it is
Most US women's brands map letter sizes to numbers like this:
| Letter | US numeric | Bust | Waist | Hip |
|---|---|---|---|---|
| XS | 0 to 2 | 32 to 33 in | 24 to 26 in | 34 to 36 in |
| S | 4 to 6 | 34 to 35 in | 26 to 28 in | 36 to 38 in |
| M | 8 to 10 | 36 to 38 in | 28 to 31 in | 38 to 40 in |
| L | 12 to 14 | 39 to 41 in | 31 to 34 in | 41 to 43 in |
| XL | 16 to 18 | 42 to 44 in | 34 to 37 in | 44 to 46 in |
These ranges are typical of US women's size charts, including ours, but they aren't a standard every brand follows. Some brands map Medium to 6 to 8; some to 10 to 12. Athletic brands often cut smaller. That's why you'll be a Medium in one shop and a Large in another without your body changing at all. Our women's shirt size chart and women's dress size chart go into more detail.
Women's Medium in other countries
| System | Medium is usually |
|---|---|
| US | 8 to 10 |
| UK | 12 to 14 |
| EU (France, Germany) | 40 to 42 |
| Italy | 44 to 46 |
| Australia | 12 to 14 |
| Japan | 11 to 13 (but Japanese M runs small; see below) |
UK sizes are usually US plus 4, and EU sizes about US plus 32, which is how a US 8 becomes a UK 12 and an EU 40. Our US to UK and US to EU converters do the maths for every size.
Men's Medium: chest, waist and collar
Men's letter sizes are usually tied to chest measurement:
| Letter | Chest | Waist | Collar (dress shirts) |
|---|---|---|---|
| S | 35 to 37 in | 29 to 31 in | 14 to 14½ in |
| M | 38 to 40 in | 32 to 34 in | 15 to 15½ in |
| L | 41 to 43 in | 35 to 37 in | 16 to 16½ in |
| XL | 44 to 46 in | 38 to 40 in | 17 to 17½ in |
| XXL | 47 to 49 in | 41 to 43 in | 18 to 18½ in |
So a man with a 39-inch chest is usually a Medium in T-shirts, sweaters and casual shirts. In dress shirts, he'd look for a 15 or 15½ collar instead of a letter. Our explainers on what neck 16 means and what sleeve 32/33 means cover dress shirt sizing.
In trousers, a men's Medium usually corresponds to a 32 or 33 waist. If you see "M" on joggers or shorts, check whether the brand lists the waist in inches, as elastic waists stretch differently.
Men's Medium in other countries
| System | Medium is usually |
|---|---|
| US / UK | M, chest 38 to 40 in |
| EU jacket / suit | 48 to 50 |
| EU shirt collar | 38 to 39 |
| Japan | L (Japanese sizes run small) |
European suit and jacket sizes are roughly chest in inches plus 10, which is how a 38 to 40 inch chest becomes an EU 48 to 50. See our men's suit size conversion for the full table.
Kids' Medium
In US children's clothing, letter sizes usually map to numeric sizes like this:
| Kids' letter | Usual numeric size | Rough height |
|---|---|---|
| XS | 4 to 5 | about 40 to 44 in |
| S | 6 to 7 | about 45 to 49 in |
| M | 7 to 8 (some brands 8 to 10) | about 49 to 53 in |
| L | 10 to 12 | about 54 to 59 in |
| XL | 14 to 16 | about 60 to 64 in |
Kids' letter sizes vary even more than adults', and girls' and boys' ranges often differ. Go by height and chest rather than age. A tall 6-year-old may already need a Medium. The kids' clothing size chart and kids' clothing size calculator help.
Why Medium means different things in different brands
There's no law that says what "Medium" is. Each brand designs around its own fit model and target customer. A few forces push sizes around:
- Vanity sizing. Over the decades, many brands have made sizes bigger while keeping the labels the same, so today's US 8 is larger than a US 8 from decades ago. Our explainer on vanity sizing goes into why.
- Fit style. A slim-fit Medium and a relaxed-fit Medium can differ by several inches in the chest.
- Target market. A brand selling mainly to younger customers often cuts smaller than one selling to older customers.
- Region. Asian brands generally cut smaller than US and European brands.
Asian Medium runs small
If you're buying from a Japanese, Korean or Chinese brand, expect their Medium to fit like a US Small, and sometimes an Extra Small. Their size charts are designed for their home market. Always check the measurements. Our guides on why Japanese sizes run smaller and the Asian size to US size converter help translate.
The average body isn't a Medium
It's easy to assume "Medium" means "average." It doesn't, at least not in the US any more. CDC body measurement data puts the average waist circumference of US adults at about 38.5 inches for women and 40.6 inches for men (2021 to 2023 survey data). Both are well above the waist range of a typical Medium in the tables above.
That isn't a judgement about anyone's body. It's a sign that letter sizes were set decades ago around a different "average", and that you shouldn't feel you "should" be a Medium. Pick the size that fits your measurements.
How to find your size instead of guessing
- Measure yourself. Bust or chest, waist and hips take two minutes with a soft tape. See our guides to measuring your chest, bust and waist.
- Find the brand's size chart and compare your numbers, not your usual letter.
- If you're between sizes, size up for structured pieces (blazers, button-ups, woven trousers) and down for stretchy pieces (leggings, knit tops, stretch jeans).
- Read the fit description (slim, regular, relaxed, oversized) and the model's size.
- Use a size calculator if you'd rather not do the maths. The women's clothing size calculator and men's clothing size calculator work from your measurements.
Medium by type of garment
The same Medium can fit very differently depending on what you're buying:
| Garment | How a Medium tends to fit | What to check |
|---|---|---|
| T-shirts | Close to the chart, but "oversized" styles run big on purpose | Chest width laid flat, body length |
| Hoodies and sweatshirts | Often roomy, with dropped shoulders | Chest and length; size down if you want a closer fit |
| Jackets and coats | Cut with room for layers | Chest and sleeve length; don't size up for layers unless the brand says to |
| Activewear | Often cut small and tight, especially compression styles | Waist and hip on leggings, bust on sports tops |
| Jeans | Usually sold by waist and inseam instead | Your waist in inches, not "M" |
| Sleepwear and loungewear | Loose and forgiving | Length on tall or petite bodies |
| Dresses | Depends on structure | Bust and waist for fitted styles, length for loose ones |
So "I'm always a Medium" is really "I'm a Medium in the brands and styles I usually buy." Change brand or style and you may move a size either way.
Two worked examples
A woman with a 37-inch bust, 30-inch waist and 40-inch hips sits right in the Medium row of the women's table above. In a US brand that maps Medium to 8 to 10, she's a Medium. In a UK brand she'd look for a 12 or 14, and in a European brand a 40 or 42. In a Korean or Japanese brand, she'd likely need an L or XL. If a dress is fitted at the waist, she'd check the waist measurement on that dress's chart, since her waist is near the top of the Medium range.
A man with a 39-inch chest and a 33-inch waist is a Medium in most T-shirts and sweaters. For a dress shirt, he'd measure his neck instead and buy by collar size, probably 15 or 15½. For trousers he'd buy a 33 waist rather than a Medium. In a slim-fit shirt, his chest is fine but he might size up if he likes room through the arms.
Medium vs other sizes
A few related questions people ask:
- What number size is a Small? Usually US women's 4 to 6, men's chest 35 to 37 inches.
- What number size is a Large? Usually US women's 12 to 14, men's chest 41 to 43 inches.
- What number size is an XL? Usually US women's 16 to 18, men's chest 44 to 46 inches. See what number size is an XL.
- Is a Medium the same as a size 10? In many US women's brands, a 10 is the top of the Medium range. In others, it's a Large.
If you sell clothing online
Letter sizes are where a lot of wrong-size returns start, because shoppers assume a Medium is a Medium everywhere. On your product pages:
- Show the measurements behind each letter, not just S, M, L.
- Say how your sizing compares: "runs small, size up" or "true to US sizing."
- Show the model's height and size.
- If you sell internationally, show UK and EU equivalents.
Tailor Size Guide adds per-product size charts and a size recommender so shoppers see what "Medium" means for that specific product.
Frequently asked questions
What number size is a women's Medium?
Usually a US 8 to 10, for a bust of about 36 to 38 inches. Some brands map Medium to 6 to 8 or 10 to 12, so check the brand's chart.
What number size is a men's Medium?
A men's Medium usually fits a chest of 38 to 40 inches and a waist of 32 to 34 inches, with a 15 to 15½ inch collar in dress shirts.
Is a Medium a 10 or a 12?
In most US women's brands, a 10 is the top of the Medium range and a 12 is the start of Large. Brands differ, so compare your measurements with the brand's chart.
What is a Medium in UK sizes?
A US women's Medium (8 to 10) is usually a UK 12 to 14. Men's letter sizes are generally the same in the US and UK.
What is a Medium in EU sizes?
A women's Medium is usually EU 40 to 42 (Italian 44 to 46). A men's Medium is usually an EU 48 to 50 in jackets.
Why does my Medium fit differently in different brands?
There's no universal standard. Each brand sets its own sizes around its fit model and target customer, and fit styles like slim or relaxed change the measurements too.
What is a kids' Medium?
In US children's clothing a Medium is usually a size 7 to 8, for a child about 49 to 53 inches tall. Go by height and chest, not age.
Sources and standards
- CDC National Center for Health Statistics, FastStats: Body MeasurementsAverage waist circumference of US adults aged 20 and over: about 38.5 inches for women and 40.6 inches for men (NHANES, August 2021 to August 2023).
- Tailor Size Guide size chartsThe letter-to-number and measurement ranges are typical of US size charts, including ours. Individual brands vary.
- International size conversion conventionsUK women's sizes usually run US plus 4, EU about US plus 32, and EU men's jackets about chest in inches plus 10.
Put the right size chart on every product
Tailor Size Guide adds per-product size charts, a cm/inch toggle, and a fit recommender to Shopify product pages, with no theme code.