Shirt sizes come in three families: casual letter sizes (S, M, L), dress shirts with a neck and sleeve measurement (15½/34), and women’s numeric sizes. This calculator handles all three from a few tape-measure readings. Men enter chest and neck; women enter bust. The result uses Nike’s body-measurement chart and, for men, Stetson’s dress shirt guide.
How to use the shirt size calculator
- Choose men’s or women’s sizing.
- Measure your chest or bust around the fullest part, tape horizontal.
- For men, measure the neck around the base, where the collar sits.
- Read the results: the casual size, the body range for it, and for men the dress-shirt size with neck and sleeve ranges.
Shirt size formula (chart lookup)
dress shirt = larger of the size by chest and the size by neck
between sizes → go up
The ranges are copied from Nike’s tops charts and from the men’s shirt guide on the Stetson size page (retrieved 2026-10-15). A measurement on the upper limit of a range belongs to that size; one in the gap between two printed Stetson ranges belongs to the larger. The centimetre columns are the inch values × 2.54.
Men’s tops (Nike, body measurements)
| Size | Chest (in) | Chest (cm) |
|---|---|---|
| XXS | 28.1 – 31.5 | 71 – 80 |
| XS | 31.5 – 35 | 80 – 89 |
| S | 35 – 37.5 | 89 – 95 |
| M | 37.5 – 41 | 95 – 104 |
| L | 41 – 44 | 104 – 112 |
| XL | 44 – 48.5 | 112 – 123 |
| XXL | 48.5 – 53.5 | 123 – 136 |
| 3XL | 53.5 – 58 | 136 – 147 |
| 4XL | 58 – 63 | 147 – 160 |
Men’s dress shirts (Stetson)
| Size | Neck (in) | Chest (in) | Waist (in) | Sleeve (in) |
|---|---|---|---|---|
| S | 14 – 14.5 | 35 – 37 | 29 – 31 | 32.5–33 |
| M | 15 – 15.5 | 38 – 40 | 32 – 34 | 33.5–34 |
| L | 16 – 16.5 | 41 – 43 | 35 – 37 | 34.5–35 |
| XL | 17 – 17.5 | 44 – 46 | 38 – 40 | 35.5–36 |
| 2XL | 18 – 18.5 | 47 – 49 | 41 – 43 | 36 |
| 3XL | 19 – 19.5 | 50 – 52 | 44 – 46 | 36.5 |
Women’s tops (Nike, body measurements)
| Size | Bust (in) | Bust (cm) | US | UK |
|---|---|---|---|---|
| XXS | 27.5 – 29.5 | 70 – 75 | 0 | 2 |
| XS | 29.5 – 32.5 | 75 – 83 | 0–2 | 4–6 |
| S | 32.5 – 35.5 | 83 – 90 | 4–6 | 8–10 |
| M | 35.5 – 38 | 90 – 97 | 8–10 | 12–14 |
| L | 38 – 41 | 97 – 104 | 12–14 | 16–18 |
| XL | 41 – 44.5 | 104 – 113 | 16–18 | 20–22 |
| XXL | 44.5 – 48.5 | 113 – 123 | 20–22 | 24–26 |
Worked example
A man measures chest 40 in and neck 15½ in.
- Casual size: chest 40 is within the 37.5 to 41 band → M.
- Dress shirt: chest 40 is within 38–40 (M) and neck 15½ is within 15–15½ (M) → M, neck 15–15.5 in, sleeve 33.5–34 in.
A woman with a 36 in bust lands in M (bust 35.5–38 in), US 8–10.
Choosing between sizes
- Slim versus regular cuts: a slim fit runs closer; if you prefer room, go up a size.
- Collar test: you should be able to slip a finger between a buttoned collar and your neck.
- Sleeve length can be altered by a tailor more easily than the body of the shirt.
- Fabric: cotton shrinks a little when washed, so allow for it.
To convert letters into numbers see the Letter Size to Number Converter (S/M/L) converter; for trousers see Pants / Trouser Size Calculator and for dresses Dress Size Calculator. This page gives general guidance only.
Sources
Every figure above comes from these pages, read directly on the dates shown. Brand names are used only to identify published charts.
- Nike — men’s tops size chart (chest, waist, hip) — checked 2026-10-15
- Nike — women’s tops size chart (bust, US/UK conversions) — checked 2026-10-15
- Stetson — size chart, including the men’s shirt size guide (neck, chest, waist, arms) — checked 2026-10-15
Frequently asked questions
How do I measure my chest for a shirt?
Wrap a tape around the fullest part of your chest or bust, under the arms and across the shoulder blades, keeping it horizontal and snug but not tight. Stand relaxed with your arms down.
How do I measure my neck size for dress shirts?
Measure around the base of the neck where the collar sits, with one finger between tape and neck. Dress-shirt neck sizes move in half inches, and the Stetson chart pairs each neck range with a chest range and a sleeve length.
What if the chest and neck point to different sizes?
Take the larger size of the two for men. A collar that is too tight is more uncomfortable than a shirt that is a little loose, and the calculator shows the dress-shirt size that satisfies both measurements.
What does the sleeve length mean?
It is measured with the arm bent about 90 degrees from the bone at the centre back of the neck, over the shoulder and along the outside of the arm to the wrist bone, as in Stetson’s instructions.
Do women’s shirt sizes follow the same method?
Women’s tops use the bust measurement, and Nike says that if bust and waist point to different sizes you should use the bust. See Letter Size to Number Converter (S/M/L) for converting S, M, L to numeric sizes.