Title | WIAI Custom Business Suits - Made to Measure

Men's Suit Size Guide: From Measurements to Fit, Find Your Perfect Suit Easily

October 16, 2025

Choosing the right suit size is no easy task. It needs to fit your upper and lower body perfectly, ultimately creating a clean, neat silhouette that accentuates your figure without feeling restrictive. Especially when shopping online or considering a custom-made suit, relying on a suit size calculator and an accurate size chart can help you save time, effort, and unnecessary frustration. Next, this detailed guide will make it easy for you to find your perfect suit size.

1. Suit Measurements: Accurate Data is the Basis for a Fit

Stop guessing at your suit size based on the label on your jeans or shirt. Take the time to accurately measure using a suit sizing chart for a suit that's both straight and comfortable. For a more comprehensive guide, check out our detailed article, "How to Measure for a Suit." Here are the key areas to focus on when choosing the right size:

Shoulder Width: Measure from shoulder bone to shoulder bone, with your back straight.
Chest: Wrap the tape measure around the fullest part of your bust, keeping it flat and snug, but not too tight.
Waist: Measure around your natural waist, at the narrowest part of your torso (usually just above your belly button).
Hip: Stand with your feet together and wrap the tape measure around the widest part of your hips.
Sleeve Length: With your arm slightly bent, measure from the shoulder seam down to your wrist bone.
Back Length: Measure from the base of your neck to where you want the hem of your suit jacket to end.
Pants Length (Inseam): Measure from the crotch to your ankle for suit pants.
Pants Length (Outer Length): Measure from waistband down to desired hem. The exact length depends on whether you prefer a classic or modern hem.
Height: Measure from the top of your head to the ground while standing barefoot against a wall.

Pro Tips for Accurate Measurements

Even small measurement errors can affect the overall fit, so keep these pro tips in mind:

Relax your posture: Stand naturally, without pushing your chest or pulling in your stomach.
Don't overtighten the tape measure: The tape measure should fit flat against your body, not squeeze it.
Take two measurements and average the average: Consistency is key to accuracy.
Measure under your suit: Shirts or thin sweaters can affect the fit of a suit, so wear them when measuring.
Focus on the shoulder: The shoulder is the most difficult part to alter, so if you're unsure, prioritize ensuring the shoulder fit.
If you're between sizes: Always order the larger size. A tailor can fine-tune the fit by adjusting the waist, sleeves, or length.

2. Men's Suit Size Chart: Find Your Size

A standard suit size chart is a helpful guide for finding the right size, combining key measurements like chest, waist, and inseam with proportions like height and weight. But remember, these are just general guidelines; at WIAI, we custom-build suits based on your exact body measurements to achieve a truly perfect fit.

Suit Size Chart (Inches)

Below is a general guide based on inches. You can use your own measurements as a guide, but remember: the shoulders and chest are the most important and determine the overall fit of the suit jacket.

EU Size	Shoulder	Chest	Waist	Sleeve	Back Length	Hip	Inseam	Leg Length	Height (ft/in)	Weight (lbs)
44	16.5	34–35	28–29	24	28	35–36	30	40	5’6–5’7	130–145
46	17	36–37	30–31	24.5	28.5	37–38	30–31	41	5’7–5’8	145–160
48	17.5	38–39	32–33	25	29	39–40	31–32	42	5’8–5’9	160–175
50	18	40–41	34–35	25.5	29.5	41–42	32–33	43	5’9–5’10	170–185
52	18.5	42–43	36–37	26	30	43–44	33–34	44	5’10–6’0	180–195
54	19	44–45	38–39	26.5	30.5	45–46	34–35	45	6’0–6’1	190–205
56	19.5	46–47	40–41	27	31	47–48	35–36	46	6’1–6’2	200–220
58	20	48–49	42–43	27.5	31.5	49–50	36–37	47	6’2–6’3	210–230

Example: If your chest is 40 inches, you are 5'10" tall, and weigh 180 lbs, you would likely fit into a size EU 50 suit.

Suit Size Chart (Centimeters)

For those who prefer centimeters, this chart corresponds to the inches chart, especially for European sizing.

EU Size	Shoulder	Chest	Waist	Sleeve	Back Length	Hip	Inseam	Leg Length	Height	Weight
44	42	86–89	71–74	61	71	89–91	76	102	168–170	59–66
46	43	91–94	76–79	62	72	94–97	78–79	104	170–173	66–72
48	44	96–99	81–84	63	74	99–102	80–81	107	173–176	72–79
50	46	101–104	86–89	65	75	104–107	82–84	109	176–179	77–84
52	47	106–109	91–94	66	76	109–112	85–86	112	179–182	82–89
54	48	111–114	97–99	67	77	114–117	87–89	114	182–185	86–93
56	50	116–119	102–104	68	79	119–122	90–92	117	185–188	91–100
58	51	121–124	107–109	70	80	124–127	93–94	119	188–190	95–104

Example: A person who is 178 cm tall, has a chest circumference of 101 cm and weighs 80 kg would typically fit in a size EU 50 suit.

International Size Conversion Chart

If you shop between brands or countries, a conversion chart is essential. It can help you convert EU sizes to UK, US, Italian, French, and more common international sizes.

EU	US	UK	IT	FR	INT
44	34	34	44	44	XS
46	36	36	46	46	S
48	38	38	48	48	M
50	40	40	50	50	M–L
52	42	42	52	52	L
54	44	44	54	54	XL
56	46	46	56	56	XXL
58	48	48	58	58	3XL

For example, if you typically buy a UK size 40 suit, this corresponds to a EU size 50 and a US size 40, which falls into the M–L range in international sizing.

Note that sizing may vary slightly between brands or tailor shops. Always check the brand's official size chart before purchasing.

3. Suit Fit Standards: Determine if your suit fits you perfectly

Even if you've chosen the right size from the sizing chart, the true fit of a suit still needs to be determined by how it fits. A well-fitting suit should be clean, slim, and comfortable:

Jackets: The shoulder seams should fall directly on the shoulder bones, neither drooping nor straining. When buttoned, the bust should close easily without feeling constricted, and the jacket should be slightly cinched at the waist for a tailored look. Sleeves should reach the wrist, leaving approximately 0.5 inches of shirt cuff visible.
Pants: The waist should fit snugly, securely in place without a belt, and the hips should offer ample room for movement without feeling constricted. The inseam should match the length of the leg, and the hem should have either a classic hem (subtle pleating above the shoe) or a modern straight hem (a clean, straight line above the shoe).

A perfectly fitted suit should have smooth lines, flatter the figure, and move naturally with the body. If it appears to be puckered, tight, or has excessive seams, recheck your measurements or consider alterations.

4. Choose the size according to the suit type: different styles of adaptation skills

Not all suits are cut the same, and the style you choose will directly impact the size that will suit you best.

Slim Fit: A slim-fit blazer features a more pronounced nipped-in waist and chest, creating a smooth, close-fitting silhouette. The sleeves and legs are narrower, so if you're between sizes or have a larger build, you may want to size up to avoid constriction or restricted movement when buttoning
Regular Fit: This is the most balanced cut, offering ample room in the chest and waist without appearing bulky. The sleeve and trouser proportions are classic, making it the safest choice for most body types. Unless you need extra room for layering, order your standard size.
Loose/Modern Fit: Often referred to as a "modern loose fit," this cut offers more room in the chest, waist, and legs while still maintaining a clean silhouette. It's ideal for those with wider figures or those seeking comfort without sacrificing style. If you're used to slim fits, you may notice a slightly longer drape and a slightly longer silhouette.

Suit styles

Different suit designs can also influence sizing, as details in the construction can alter the garment's drape.

Single-breasted suits: With only one row of buttons and a narrow overlap, they are the most versatile style. These suits typically fit true to size, making small adjustments to the waist or sleeves easier.
Double-breasted suits: With a wider overlap and more fabric in the torso, they may feel constricting. If you have a wider chest, it's recommended to size up or opt for a cut with more room in the chest to maintain a clean silhouette while ensuring comfort.
Unstructured suits: With a lightweight structure and lack of heavy shoulder padding, they allow for more natural movement and a more tailored fit. Without the rigid structure of a traditional tailored suit, they can be more forgiving in terms of fit, but accurate measurements are still important.
Structured suits: With padded shoulders and a defined silhouette, they maintain the garment's shape and create a sharp, clean look. These suits require more precise sizing, as the shoulder padding and cut leave little room for adjustment.

Special type of suit

Formal suits like evening gowns and morning coats follow stricter tailoring rules. Evening gowns are often tailored to create a more refined look, while morning coats are often longer and require precise measurements in the shoulders and chest to maintain balance. In both cases, precision is crucial, and even a half-size error can be noticeable.

5. Choose the size according to your body shape: let the suit show off your figure

Understanding your body shape and size is just as important as knowing your measurements. A suit that fits one body type may need to be adjusted for another.

Body type

Rectangular body shape: The shoulders, waist, and hips are nearly equal in width. Choose a suit with a tapered waist and structured shoulders to add dimension.
Triangular body shape: The hips are wider than the shoulders. A slightly longer jacket with structured shoulders can balance the proportions. Opt for straight-leg pants to avoid being too tight around the hips.
Inverted triangle body shape: The shoulders are broad and the waist is narrow. Choose a suit with softer shoulders and well-proportioned lapels to avoid appearing too bulky in the upper body. Opt for slightly wider pants to balance the overall proportions.
Oval body shape: The abdomen is rounder. A single-breasted suit with darts can be slimming, but avoid overly slim-fitting styles that emphasize the waist.
Trapezoidal body shape: Considered a "muscular" body shape, it has broader shoulders and chest, with a well-proportioned waist and hips. Most suit cuts are suitable for this body shape, making it the most versatile.

body shape

Tall: Wider builds often require extra room in the chest, waist, and thighs. Choose a suit with slightly wider lapels and structured shoulders for balance. Opt for a regular or loose fit to avoid constriction when buttoning; opt for straight-leg trousers to maintain a clean silhouette.
Tall: Tall men should pay special attention to jacket and sleeve length. A jacket that's too short will immediately look out of place. A longer jacket and trousers with appropriately hemmed hems will help maintain a balanced overall proportion.
Short: Short men should avoid excessive fabric, which can make them appear smaller. Opt for slim or modern fits, with jackets that are slightly shorter and buttons placed slightly higher to elongate the torso. Pants with minimal hems can make the legs appear longer.
Petite: Slender men can easily look bulky in loose-fitting styles. Opt for a slim or regular fit to add dimension without exaggerating the figure. Narrow lapels and tailored, clean-lined trousers help maintain proportions and a sharp look.

6. Bespoke suits: the ideal choice for a perfect fit

Remember, even the most detailed suit size chart can't guarantee a perfect fit. Standard sizes are based on averages, but no one's body perfectly fits averages. Therefore, a custom-made suit is a wiser choice.

At WIAI, we tailor our suits to your exact measurements, ensuring they fit snugly and move with you. Beyond just your size, you can customize every detail: from fabric and lapel style to lining, trouser cut, and even button placement. Whether you want a classic navy business suit, a stylish double-breasted blazer, or a lightweight summer linen blazer, the design is entirely up to you.

Best of all, this custom service is very affordable, often comparable to mid-range ready-to-wear suits, but with a far superior fit. Choosing WIAI means you're not just buying a suit; you're investing in exquisite craftsmanship, personalized style, and a perfect fit every time you wear it.

7. Frequently Asked Questions about Suit Size Charts

How do I know my suit size?

First, take accurate measurements, including shoulder width, chest circumference, waist circumference, hip circumference, sleeve length, back length, trouser length inseam, trouser length outside length, height and weight, and then compare these data with the suit size chart. A simple rule of thumb is that chest circumference (measured around the fullest part of the chest) determines the size of the jacket, while waist circumference and trouser length inseam determine the size of the trousers. Prioritize making sure the shoulder size fits (the shoulder is the most difficult to modify). If you are between two sizes, choose the larger size and then modify the waist, sleeves or trouser legs. For detailed measurement steps, see "How to Measure a Suit" and compare the men's suit size chart (inches and centimeters) and the international size conversion chart.

What size does a UK men's suit size 42/44 correspond to?

In the UK sizing system, numbers typically represent chest inches. According to our conversion chart, a UK size 42 is approximately equivalent to a EU size 52, a US size 42, and an international size L; a UK size 44 is approximately equivalent to a EU size 54, a US size 44, and an international size XL. We recommend using your actual chest, waist, and inseam measurements to confirm this. The conversion chart is for reference only, and cuts may vary between brands.

What does a 38R suit size mean?

A 38R designation indicates a 38-inch chest circumference and a regular-length jacket. In our size chart, this roughly corresponds to EU size 48, UK size 38, US size 38, and international size M, and typically fits someone of average height (approximately 5'8"–5'9" / 173–176 cm). Pants paired with a 38R jacket typically have a standard rise, and the inseam can be modified to suit your preference (a slight hem or a modern, no-hem style is recommended). If you're shorter than approximately 5'7" (170 cm), consider a 38S; if you're taller than approximately 5'11" (180 cm), consider a 38L.

When in between sizes, should I size up or down?

Choose a larger size and then alter the waist, sleeves, or hems. It's much easier to alter a smaller suit than to make it larger.

How should a suit jacket fit?

The shoulder seams should fall at the shoulder bones, the chest should be closed without feeling tight, the waist should be slightly slimmed, and the sleeves should end at the wrist bones (leaving approximately 0.5 inches / 1–1.5 cm of shirt cuff exposed).

Do height and weight matter when choosing a suit size?

Importantly, our size chart includes height and weight ranges that can be used to verify your selection. Using height and weight data in conjunction with body measurements will provide more reliable results.

When can I choose a custom-made suit without referring to a size chart?

If you're someone who frequently falls between sizes, has a larger or more unusual body type, or desires a specific drape, WIAI's custom suits take the guesswork out of tailoring to your exact measurements, ensuring a perfect fit.

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