Mens Shirt Size Calculator

Unit System

Input Method

Shirt Type

Neck Circumference

Measure around the base of your neck. Leave room for 1–2 fingers.

Chest Circumference

Measure at the fullest point, under armpits, parallel to the floor.

Sleeve Length

Center back of neck, over shoulder (elbow slightly bent), to wrist bone.

Waist Circumference (optional)

Measure at navel level, narrowest part of torso, relaxed breath.

Fit Preference

Enter Your Measurements

Fill in your neck and chest measurements — or your height and weight — to instantly find your shirt size across US, EU, UK, Japan, and Korea sizing systems.

Last updated October 20, 2018

Find your perfect shirt size in US, EU, UK, Japan, and Korea sizing systems

Finding the right shirt size should be simple, but with so many sizing systems — US, European, UK, Japanese, Korean — and different conventions for dress shirts versus casual shirts, it quickly becomes confusing. Our Men's Shirt Size Calculator takes the guesswork out of shirt shopping, whether you're buying online, in a foreign country, or ordering a dress shirt for a formal occasion. Men's dress shirts use a two-number sizing system: collar size / sleeve length (for example, 15.5 / 34). The collar number is your neck circumference in inches, with built-in ease — typically 0.5 inches more than your actual neck measurement — to ensure comfortable movement. The sleeve number measures from the center back of your neck, over your shoulder, and down to your wrist. European dress shirts convert collar size to centimeters, so a US 15.5 becomes approximately a EU 39–40 collar. Casual shirts, polos, and T-shirts typically use alpha sizing (XS, S, M, L, XL, XXL, 3XL) based on chest circumference. The same alpha size can correspond to very different chest measurements depending on the fit style. A Regular fit large might accommodate a 42–44 inch chest with 4 inches of ease, while a Slim fit large might allow only 2 inches of ease — meaning the shirt looks much narrower on the same body. Our fit comparison chart visualizes exactly how much room each fit type provides. Different brands also size differently. Brands like Zara and H&M are known to run smaller than US standard sizing, so you might need to size up. Ralph Lauren tends to run true to size or slightly large. Uniqlo's sizing varies by product line but generally aligns with US standard. Our brand-specific reference table shows you the chest range for each major brand at your recommended alpha size, so you can shop with confidence. Measuring yourself correctly is the first step to accurate sizing. For neck circumference, wrap a soft tape measure around the base of your neck, just below the Adam's apple, where your collar would sit. You should be able to slip one or two fingers under the tape — this mirrors the collar ease already built into shirt sizing. For chest circumference, measure at the fullest point of your chest, under your armpits, with the tape parallel to the floor. Keep your arms relaxed at your sides. For sleeve length, this is the most commonly misunderstood measurement: start at the center back of your neck (not the shoulder seam), run the tape over your shoulder with your elbow slightly bent, and end at your wrist bone. For waist, measure at the narrowest point of your torso, typically at navel level, with a relaxed breath. If you don't have a tape measure handy, our height and weight estimation mode gives a rough size based on body stats. This is less precise than actual measurements — the same height and weight can correspond to very different builds — but it's a useful starting point when tape-measure access is limited. We recommend confirming with actual measurements before purchasing dress shirts or tailored clothing. Our calculator supports both Imperial (inches, feet, pounds) and Metric (centimeters, kilograms) inputs, and it covers four shirt types: Dress Shirt (neck/sleeve sizing), Casual Shirt, Polo, and T-Shirt (all chest-based alpha sizing). For each type, you can select your preferred fit — Regular, Slim, Athletic/Muscle, or Relaxed — and the calculator adjusts the recommendation accordingly. Athletic fit sizing, in particular, prioritizes chest measurement over neck, since broader shoulders and chest are the limiting factor for this body type.

Understanding Men's Shirt Sizing

What Is Men's Shirt Sizing?

Men's shirts use two main sizing conventions. Dress shirts use a numerical system based on collar size (neck circumference in inches) and sleeve length — expressed as 'collar / sleeve', for example '15.5 / 34'. This system is used in the US and UK, where both measurements are in inches. European (EU) dress shirts convert the collar measurement to centimeters, so a US 15.5 collar becomes a EU 39–40. Casual shirts, T-shirts, and polos use alpha sizing (XS through 3XL) based primarily on chest circumference. Alpha sizes correspond to chest measurement ranges — a Medium typically fits a chest of 38–40 inches — but exact ranges vary by brand and fit style.

How Is Shirt Size Calculated?

For dress shirts, your collar size is determined by your neck circumference rounded up to the nearest half inch, plus 0.5 inches of ease. If your neck measures 15 inches, your collar size is 15.5. Sleeve length is measured from the center back of the neck, over the shoulder, to the wrist. Your EU collar size equals your neck circumference in centimeters (neck inches × 2.54), rounded to the nearest whole number. For casual shirts, alpha size is determined by comparing your chest circumference to standard size ranges. Fit preference (Slim, Regular, Athletic, Relaxed) shifts the recommendation — Slim fit subtracts 1–2 inches of ease; Relaxed sizing may move you up a size for extra room.

Why Does Getting the Right Size Matter?

An ill-fitting shirt affects both comfort and appearance significantly. A collar that is too tight restricts movement and breathing throughout the day; one that is too loose looks sloppy and allows the collar to shift. Sleeve length that is too short rides up the arm; too long and the sleeve bunches at the wrist. For dress shirts worn with a suit or blazer, about half an inch of shirt cuff should show below the jacket sleeve — achievable only with the correct sleeve length. For casual shirts, a chest that is too tight across the shoulders restricts movement and can cause stress seams to split, while an overly large chest looks shapeless. Correct sizing also affects how a shirt sits at the waist and hem length.

Limitations and Caveats

Our calculator uses standard US sizing tables as the primary reference. Individual brands may size differently — Zara and H&M tend to run small, Ralph Lauren tends to run true to size or slightly large, and Uniqlo sizing varies by product line. The height/weight estimation mode is less accurate than body measurements and should be used only as a rough guide. Additionally, shirt sizing does not account for body proportions: someone with a broad chest but narrow shoulders, or long torso but short arms, may find standard sizing imperfect regardless of which size they select. Consider measuring multiple points and, when possible, trying shirts on or using brand-specific size guides before purchasing formal or tailored shirts.

Men's Shirt Sizing Formulas

Collar Size from Neck Measurement

Collar Size = Neck Circumference + 0.5"

Dress shirt collar size is your neck circumference rounded up to the nearest half inch, plus 0.5 inches of ease. This built-in ease allows you to comfortably fit one to two fingers under the collar. If your neck measures 15 inches, your collar size is 15.5.

Sleeve Length Measurement

Sleeve = Center Back of Neck → Shoulder → Wrist (elbow slightly bent)

Sleeve length is measured from the center back of your neck, across your shoulder point, down your arm with the elbow slightly bent at a natural angle, to the wrist bone. This is NOT the same as arm length measured from shoulder to wrist — the center-back starting point adds 6–8 inches.

US Collar to EU Collar Conversion

EU Collar (cm) = US Collar (inches) × 2.54, rounded to nearest whole number

European dress shirts express collar size in centimeters. A US 15.5 collar converts to approximately 39 cm (15.5 × 2.54 = 39.37). Standard EU collar sizes run 36, 37, 38, 39, 40, 41, 42, 43, 44, 45.

Chest Ease by Fit Type

Shirt Chest = Body Chest + Ease (Regular: 4–6", Slim: 1–3", Athletic: 4–6" chest / 2–3" waist, Relaxed: 6–8")

The ease — extra room beyond body measurements — varies by fit type. Regular fit provides 4–6 inches of ease for comfortable movement. Slim fit uses only 1–3 inches for a tailored silhouette. Athletic fit adds extra room at the chest and shoulders but tapers at the waist. Relaxed fit provides 6–8 inches for maximum comfort.

Men's Shirt Size Reference Charts

Men's Dress Shirt Sizes — Collar and Sleeve

Standard men's dress shirt sizes showing collar size in US inches and EU centimeters, with corresponding alpha size and typical sleeve length ranges. US and UK collar sizes are identical.

Collar (US/UK)	Collar (EU cm)	Alpha Size	Sleeve Range (in)
14	36	XS	32–33
14.5	37	S	32–33
15	38	S	32–34
15.5	39–40	M	33–34
16	41	M	33–35
16.5	42	L	34–35
17	43	L	34–36
17.5	44	XL	35–36
18	45–46	XL	35–36
18.5	47	XXL	35–37
19	48	XXL	36–37
20	50–51	3XL	36–37

Men's Casual Shirt Sizes (S–3XL) with Body Measurements

Alpha size chart for casual shirts, polos, and T-shirts showing chest and waist measurement ranges in inches. US and EU size comparisons included.

Alpha Size	Chest (in)	Waist (in)	US/UK Collar Equiv.	EU Size
XS	33–35	27–29	14	44
S	35–37	29–31	14.5–15	46
M	38–40	32–34	15.5–16	48–50
L	41–43	35–37	16.5–17	52–54
XL	44–46	38–40	17.5–18	56–58
XXL	47–49	41–43	18.5–19	60–62
3XL	50–52	44–46	19.5–20	64–66

Worked Examples

Determine Dress Shirt Size from 16" Neck and 34" Sleeve

A man measures his neck at 15.5 inches (with two-finger ease) and his sleeve length from center back to wrist at 34 inches. He needs his dress shirt size.

Add collar ease: 15.5" + 0.5" = 16" collar size.

Sleeve length is already measured correctly at 34 inches.

US/UK dress shirt size: 16/34.

Convert collar to EU: 16 × 2.54 = 40.64, rounded to EU 41.

Alpha size equivalent: M (based on 16" collar range).

US/UK dress shirt size 16/34, EU collar 41, Alpha M. When ordering, look for shirts labeled 16-34 or 16-34/35 (half-inch sleeve increments are common).

Find Casual Shirt Size for 42" Chest

A man has a chest circumference of 42 inches and wants to find his casual shirt size in Regular fit.

Look up 42" chest in the casual size chart.

42" falls in the L range (41–43 inches).

For Regular fit with 4–6 inches of ease, L provides adequate room.

For Slim fit (1–3" ease), he might consider XL for more room across the chest.

EU casual equivalent: 52–54.

Casual shirt size L (Regular fit) for a 42" chest. EU size 52–54. For Slim fit, try both L and XL and compare the feel across the shoulders and chest.

How to Use This Calculator

Choose Your Unit System and Shirt Type

Select Inches/lbs or Centimeters/kg at the top of the form. Then choose your shirt type: Dress Shirt uses collar/sleeve sizing, while Casual, Polo, and T-Shirt use chest-based alpha sizing. The most relevant measurements will appear automatically.

Enter Your Body Measurements

Measure neck circumference at the base of your neck (add 1–2 finger room), chest at the fullest point under your armpits, sleeve from center back neck over shoulder to wrist, and waist at navel level. If you don't have a tape measure, switch to Height & Weight mode for an estimate.

Select Your Fit Preference

Choose Regular for standard room, Slim for a fitted silhouette, Athletic for broader chest with tapered waist, or Relaxed for comfort. The calculator adjusts its recommendation based on your fit preference and shows you a visual comparison of how each fit differs in ease of movement.

Read Your Results Across All Size Systems

Your recommended size displays in US, EU, UK, Japan, and Korea sizing. For dress shirts you also get the collar/sleeve numerical format. Check the brand-specific notes to adjust for your target brand, and export or print results to keep when shopping.

Frequently Asked Questions

What does a dress shirt size like 15.5/34 mean?

A dress shirt size like 15.5/34 has two components: the collar size and the sleeve length, both in inches. The first number (15.5) is the collar size, which corresponds to a neck circumference of approximately 15 inches — the 0.5-inch difference is built-in ease for comfort. The second number (34) is the sleeve length measured from the center back of your neck, over your shoulder, to your wrist. This format is used in the US and UK. European dress shirts express only the collar as a single number in centimeters — a 15.5 US collar is approximately a EU 39–40 collar.

How do I measure my neck for shirt sizing?

To measure your neck correctly for shirt sizing, wrap a soft fabric tape measure around the base of your neck, positioned just below your Adam's apple where a shirt collar would sit. Hold the tape so you can comfortably fit one to two fingers under it — this gap represents the ease that is already built into shirt collar sizing. Round the measurement up to the nearest half inch (or whole centimeter for metric). Do not measure too tightly; a collar that fits perfectly at rest should still allow you to swallow and move your neck comfortably throughout the day without the collar digging in.

Are US and UK shirt sizes the same?

Yes, US and UK men's dress shirt collar sizes are identical. Both use inches for neck circumference and sleeve length. A US 15.5/34 shirt is the same collar and sleeve specification as a UK 15.5/34. The main difference is in casual shirt sizing conventions and labeling — UK casual shirts sometimes show a chest measurement in inches on the label rather than alpha sizing. EU shirts, by contrast, use centimeters for collar size (a single number like 39, 40, or 41), which is why a conversion lookup is needed when shopping European brands.

What is the difference between Regular, Slim, and Athletic fit shirts?

Fit type describes how much extra room (called 'ease') the shirt has beyond your body measurement. Regular or Classic fit typically has 4–6 inches of ease at the chest, giving a relaxed drape suitable for most body types. Slim or Tailored fit has 1–3 inches of ease, creating a more fitted silhouette that tapers at the waist. Athletic or Muscle fit is designed for broader shoulders and chest with a tapered waist — it provides extra room across the chest and upper arms but less at the waist. If you have a broader chest relative to your neck, Athletic fit often works better than sizing up in Regular.

Why do brands like Zara and Uniqlo size differently than US standard?

Brands develop their own size blocks based on their target customer demographic and aesthetic positioning. Zara and H&M, for example, are positioned as fashion-forward European brands and often cut their garments slimmer than US standard, so their Medium may fit a chest that US standard considers a Small. Uniqlo sizing varies by product — some lines match US standard while others run smaller. Ralph Lauren tends to run true to US size or slightly generous. Always check a brand's specific size chart and, when available, customer reviews about fit before purchasing. Our brand-specific notes show approximate chest ranges for each brand as a starting reference.

How accurate is the height and weight estimation mode?

The height and weight estimation mode provides a rough starting point but is significantly less accurate than body measurements. The same height and weight can correspond to very different body proportions — someone who is 5'10" and 175 lbs might be slender with a narrow chest, or muscular with a broad chest and shoulders, and these two people would need completely different shirt sizes. The estimation works best for average body types and should be used only when you do not have access to a tape measure. For dress shirts, formal occasions, or online purchases without easy returns, we strongly recommend taking actual body measurements for accurate sizing.

Mens Shirt Size Calculator