Nonchalant Guide

How to Choose the Right Jacket Size Online and Measure Properly

Choosing a jacket online is not as difficult as it may seem, as long as you know what to measure and what to look for. The size number is only the beginning. What really matters are the shoulders, chest, length and overall proportion. In this guide, I will show you what to focus on when choosing the right jacket size and which details deserve the most attention.

The right jacket size is not only about the number on the label. It is mainly about how the jacket sits on the shoulders, across the chest and within the overall silhouette.

Why the size number alone is not enough

With a T-shirt, sweater or overshirt, size is often fairly easy to estimate. If the piece is slightly roomier, it usually does not matter too much. A jacket is different. It has structure, shoulders, shaping, lining, lapels and a certain architecture. That is why it behaves very differently on the body than a simple layer of clothing.

The size number is a useful starting point, but it should never be the only thing you rely on. A size 50 may fit very well from one brand, while another size 50 can be too narrow in the shoulders, too short in length or too loose around the waist. The differences come from the cut, country of origin, era, brand and whether the jacket has a slimmer silhouette or a more classic fit with greater comfort.

At Nonchalant, I therefore do not look only at the number on the label when it comes to jackets and suits. Specific measurements matter more. They tell you far more during online selection than the size alone. If a customer is deciding between two pieces, I always try to look first at the shoulders, chest, length and overall character of the jacket.

Start by measuring a jacket that already fits you well

The best way to choose a jacket size online is not to measure your body first, but to measure a jacket you already own and feel good in. Ideally, it should be a jacket that fits well in the shoulders, does not pull across the chest and feels right in its overall proportion. That jacket is your personal size chart.

Lay it buttoned on a flat surface, preferably a table or a bed. Do not stretch the fabric; just smooth it out gently. Then measure the shoulder width, chest, waist, sleeve length and full back length. Write these measurements down and compare them with the measurements listed on the product page.

The most accurate method is to compare product measurements with a jacket you already own and know fits you well.

Shoulders: the most important measurement of a jacket

The shoulders are, in my opinion, the most important part of a jacket. If the shoulders fit, smaller imperfections can often be worked with. If they do not, the jacket will usually never look right. A sleeve can be shortened, the waist can sometimes be adjusted, but badly chosen shoulders are a real problem.

The shoulder seam should end roughly where your natural shoulder ends. If it falls too far down, the jacket will look too large and tired. If it is too narrow, the sleeve will start pulling upwards and unnatural creases will appear around the upper arm.

It is worth remembering that different jacket styles treat the shoulder differently. An Italian jacket can have a softer shoulder, while British tailoring often feels more structured. But the basic rule remains the same: the shoulder should look natural. It should not make you look like a goalkeeper, nor like someone who borrowed a jacket one size too small.

Chest and waist: room, but not excess

The chest is another important area. A jacket should fasten without obvious pulling. If a sharp X shape forms around the button when the jacket is closed, the jacket is usually too small. Slight tension can be normal in some cuts, but if the fabric looks as if it is fighting against the body, the size is not ideal.

At the same time, the jacket should not hang like a coat. A well-fitting jacket should follow the body without squeezing it. I think a common mistake is that men are often afraid of a little room when choosing a jacket. Yet that small amount of space is often what decides whether the jacket looks naturally elegant or simply too tight.

The waist can be gently shaped. It does not have to be glued to the body. Classic elegance, in my view, needs a little air. A jacket should allow normal movement, sitting down, shaking hands and standing naturally. If you have to stand completely still for the jacket to look good, it is probably not the right jacket for real life.

Jacket length and sleeve length

Jacket length has a major effect on the proportions of the whole body. A jacket that is too short may look sharper at first glance, but in everyday wear it often disrupts the silhouette and creates the impression that the jacket has been cut off. A jacket that is too long, on the other hand, can make the body look heavy, especially if it does not correspond to your height and build.

I usually follow a simple rule: when you stand naturally with your arms relaxed by your sides, the bottom edge of the jacket should end approximately around the knuckles of your hand. It is not a mathematical rule for every body type, but it works very well as a point of orientation. The length of the jacket should simply make sense in relation to your height, leg length and overall silhouette.

Sleeves are slightly less critical because they can often be altered. Ideally, a small amount of shirt cuff should show beneath the jacket sleeve. If the sleeves are slightly long, that does not have to be a reason to reject the jacket, provided the rest fits well. You only need to account for a possible alteration. I would be more careful with jackets that have functional buttonholes on the sleeves, as adjustments there can be more complicated.

How to tell that a jacket does not fit

When trying on a jacket or checking measurements, pay attention mainly to the following signs. Not every small detail is a serious problem, but if several of them appear at once, the size is probably not right.

• The jacket is too small if it pulls strongly around the button, creates sharp creases across the chest or limits natural arm movement.
• The jacket is too large if the shoulders fall beyond the natural line of the body, the chest stands away and the whole silhouette feels heavy.
• The shoulders do not fit if the seam ends too far beyond the shoulder or, on the contrary, too high before the natural shoulder point.
• The length is not ideal if the jacket looks cut off or makes the upper body appear disproportionately long.
• The cut is not right for you if the measurements seem correct, but the jacket still does not feel natural. That can happen too.

In my opinion, it is better to admit that a particular cut is not right for your body than to try to save the jacket at all costs. Good clothing should not force you to adapt to it. It should help you look naturally better.

What can be altered and what is a problem

With jackets, it is important to distinguish between a normal alteration and a structural problem. Small alterations are a normal part of classic clothing. There is no need to expect every ready-to-wear piece to fit perfectly straight out of the box. What matters is that the foundation is right.

Sleeve length can usually be adjusted, the waist can often be shaped slightly, and small corrections to length may sometimes be possible. With a suit, the trousers are often altered as well. These are normal adjustments. Shoulders, a chest that is too tight or a significantly wrong jacket length are much harder to correct, and sometimes not worth correcting at all.

That is why, when choosing a jacket online, I would always start with the things that cannot easily be changed: shoulders, chest and overall proportion. If these are right, a minor sleeve alteration is usually not a problem. If they are wrong, even a beautiful fabric, a good brand or an attractive price will not save the jacket.

What to send me if you are unsure about the size

Because Nonchalant is not an anonymous warehouse, I try to give size advice as specifically as possible. If you are not sure whether a particular jacket or suit will fit you, write to me. The best information to send is your height, weight, usual jacket size and, ideally, the measurements of a jacket you already own and like.

It is even better if you can send a simple photo of yourself wearing a jacket you already have. It does not need to be professional. It is enough to see the shoulders, length and overall silhouette. Very often, that makes it clear quite quickly whether you should look for a larger size, a smaller size or simply a different cut.

And if you are in Prague or planning to visit, the best solution is a personal appointment. In the atelier, it usually takes just a few minutes to see which type of jacket suits you, which alterations make sense and what is better to avoid. With jackets, trying them on in person remains the safest route.

A well-chosen jacket does not have to be perfect to the millimetre from the beginning. What matters is that the foundation is right. If the shoulders, chest and proportions work, it can often become a piece you will wear for years. And that is exactly the direction of classic menswear that interests me most: buying less, but better.