Introduction: why sizes vary across brands
You've been there: you order a medium t-shirt, as usual, and when it arrives, it either hangs off you or squeezes your chest. Why? Because a medium is not universal. Every brand, every fit, every collection can tweak the measurements by a few centimeters. A medium at Zara is not the same as a medium at Levi's. A 32 slim doesn't fit like a 32 regular.
In men's ready-to-wear, there is no mandatory standard. Brands define their own size charts, often inspired by local norms (US, UK, EU, IT) but with tolerances. The result: men hesitate, order multiple sizes, return, waste time and money. This men's size guide has one simple goal: give you a reliable method to choose the right size, whether you're in a store or behind a screen.
We'll cover how to take your measurements, decode international conversions, understand fits, and adopt the right habits for online shopping. By the end, you'll know exactly what size to pick, even if you're between sizes.
How to take your measurements (chest, waist, hips, inseam)
Before we talk sizes, let's talk about your body. Taking your measurements is the foundation. Without them, you're flying blind. Grab a flexible tape measure, a mirror, and ideally someone to help. Wear underwear or a thin t-shirt, not thick jeans.
Chest
Wrap the tape around the fullest part of your chest, under your armpits, keeping the tape horizontal. Don't pull tight, don't puff out your chest. Note the measurement in centimeters or inches. This is your reference for tops (t-shirts, shirts, sweaters, jackets).
Waist
Place the tape at your navel, where your pants naturally sit. Breathe normally, don't suck in your stomach. This is the key measurement for pants, shorts, and belts. Note: your clothing waist size is not your actual waist measurement. A US size 32 jean often corresponds to an actual waist of 34 inches (86 cm) because brands build in ease.
Hips
Measure the widest part of your buttocks, feet together. This is crucial for pants, especially if you have developed thighs or wider hips. It prevents surprises at the thighs and crotch.
Inseam
Take a pair of pants that fit you well, lay them flat, and measure from the top of the inseam to the bottom hem. Or measure directly on your body: from the top of your inner thigh to your ankle bone. This determines your leg length (inseam). Essential for jeans and chinos.
Write down all these measurements in an app or notebook. You'll reuse them every time you shop online. It's your clothing ID card.
International size conversion chart (US, UK, EU, IT)
Sizes vary by country. A French 40 is not an Italian 40. Here's a conversion chart for tops (t-shirts, shirts, sweaters) and bottoms (pants). Keep in mind these are indicative: always check the brand's specific size guide.
Tops (t-shirts, shirts, sweaters, jackets)
US / UK: 34 = XS, 36 = S, 38 = M, 40 = L, 42 = XL, 44 = XXL
EU / FR: 36 = XS, 38 = S, 40 = M, 42 = L, 44 = XL, 46 = XXL
IT: 44 = XS, 46 = S, 48 = M, 50 = L, 52 = XL, 54 = XXL
Example: if you wear a 40 FR, you're likely a medium in France, a small in the US, and a 48 in Italy. But beware, an Italian 48 shirt may fit slimmer than an American small.
Bottoms (pants, jeans, chinos)
For bottoms, we often use waist measurements in inches (US) or centimeters (EU).
US: 28, 30, 32, 34, 36, 38 (waist in inches)
EU / FR: 36, 38, 40, 42, 44, 46 (waist in cm)
UK: 28, 30, 32, 34, 36, 38 (similar to US)
IT: 44, 46, 48, 50, 52, 54 (waist in cm, often 2 cm smaller than FR)
Conversion: 28 US = 36 EU = 44 IT; 30 US = 38 EU = 46 IT; 32 US = 40 EU = 48 IT; 34 US = 42 EU = 50 IT; 36 US = 44 EU = 52 IT; 38 US = 46 EU = 54 IT.
For jeans, inseam length is often given in inches: 30 (76 cm), 32 (81 cm), 34 (86 cm), 36 (91 cm).
"A well-dressed man is one who knows his measurements and doesn't blindly trust the label."
Fits: slim, regular, relaxed, oversized
Size isn't everything. The fit determines how the garment falls on your silhouette. Two medium t-shirts can look completely different depending on the fit. Here are the main ones.
Slim fit
Tailored, close to the body, without being tight. Armholes are higher, sleeves narrower. Ideal for slim to average builds. If you have broad shoulders or a thick torso, slim can pull at the armpits and buttons. In that case, size up or switch to regular.
Regular fit
The classic cut, straight, with a bit of ease. It's the safe bet for most body types. It doesn't cling, doesn't billow. If in doubt, start with regular.
Relaxed fit
Roomier in the chest, waist, and hips. Comfortable, casual. Perfect for tall men, broad-shouldered men, or those who like streetwear without going full oversized.
Oversized
Intentionally very loose, dropped shoulders, extra length. It's a strong stylistic choice. Warning: oversized doesn't forgive if the rest of the outfit isn't balanced. Avoid combining oversized top and bottom. An oversized top with a fitted bottom works better.
Each fit has its own measurements. A medium slim will have a 96 cm chest, a medium regular 102 cm, a medium oversized 110 cm. Hence the importance of reading the size guide and comparing with your measurements.
Tips for choosing the right size online
Online shopping is convenient but risky if you don't follow a few rules. Here's a proven method.
1. Read the brand's size guide
Don't rely on your usual size. Every site provides a table with the garment's actual measurements (chest, length, shoulder width). Compare with your measurements. If the item is pre-order or has no guide, look for reviews.
2. Consider fabric composition
A 100% cotton t-shirt can shrink 3 to 5% on the first wash. A cotton/polyester blend shrinks less. Raw unsanforized denim can lose 2 sizes. Conversely, fabric with elastane stretches. Anticipate.
3. Check the return policy
Favor sites offering free returns within 30 days. This allows you to order two sizes and return the one that doesn't fit. It's the most reliable method, especially for brands you don't know.
4. Look at model photos and reviews
Models are often 6'1" and wear a medium. If you're 5'9", rely on reviews from customers your height. Comments like "runs small" or "runs large" are gold.
5. Use a recommendation tool
Some brands offer a virtual assistant that calculates your size based on your body type and preferences. Use it.
By applying these five rules, you drastically reduce the error rate. To go further, check out our guide to choosing a men's shirt and our article on men's pants fits.
FAQ: what if I'm between sizes?
I'm between two sizes, which one should I choose?
It depends on the garment and the fit. For a top: if you're between M and L, go L if you have broad shoulders or plan to layer. Go M if you want a close fit and the fabric doesn't shrink. For pants: if you're between 32 and 34, take 33 if available, otherwise 34 and have the waist taken in by a tailor. For raw denim, size down because it will stretch.
How do I know if a garment runs small or large?
Read customer reviews and the size guide. Asian brands generally run 1 to 2 sizes small. Italian brands run slimmer. American brands run larger. Nordic brands often run large.
What if the garment doesn't fit?
Return it. Don't keep a garment that doesn't fit hoping it will adapt. An ill-fitting garment will never be comfortable or stylish. If return is impossible, see a tailor. A hem, a seam adjustment, can save a piece.
Are sizes different for jackets and coats?
Yes. Jackets and coats have specific sizes (46, 48, 50...) that correspond to chest measurement. A 48 corresponds to M/L. You also need to consider sleeve length and shoulder width. Always try on a jacket before buying, or order multiple sizes.
Final checklist for choosing the right size
Take your measurements: chest, waist, hips, inseam.
Write them down and keep them handy.
Check the brand's specific size guide.
Compare your measurements with the garment's, not with your usual size.
Consider the fit (slim, regular, relaxed, oversized).
Check fabric composition and shrinkage risk.
Read customer reviews and look at model photos.
Favor sites with free returns.
If in doubt between two sizes, order both and return one.
For important pieces, don't hesitate to use a tailor.
Actionable conclusion
Choosing the right size isn't about luck, it's about method. Take your measurements once and for all, keep them on your phone, and systematically compare them to size guides. Never trust the label alone. A medium at one brand is a large at another. Fit matters as much as size.
Next time you shop online, take two minutes to check the measurement chart. If you're between sizes, order both and return one. It's a small effort that will save you disappointment. And remember: a garment that fits well enhances your silhouette, not the other way around. To go deeper, explore our men's pants size guides and our tips on how to choose clothes online.
