When choosing a leather jacket size, simply looking at the S, M, or L tag you're used to isn't enough. The fit of the shoulders, the room around the chest, and the layers you'll wear inside the jacket should all be considered together. The right size will give you your desired look while also allowing you to sit and move your arms comfortably.
First, check what the size chart measures
A size chart might show body measurements, while another might show the product's measurements laid flat. Do not directly compare these two pieces of information. Chest circumference and product width measured armpit to armpit are not the same thing. If the chart doesn't provide an explanation, proceed by finding out the measurement method.
If product measurements are provided, place a similar jacket that fits you well on a flat surface. Measure the shoulder width, chest width, sleeve, and back length using the same method. This way, you can make a concrete comparison instead of just guessing based on a size name.
Shoulder, chest, and arm are considered together
In a classic shoulder cut, the seam is expected to sit close to the shoulder line. In dropped-shoulder designs, the seam being lower is part of the style. First, examine the intended cut of the product.
If significant pulling lines appear on the chest when you close the jacket, or if it becomes difficult to extend your arms forward, the size or fit may not be suitable for you. Also check the sleeve length with your arms relaxed and slightly bent. Don't make a decision based on the appearance in a single position.

Decide what you'll wear underneath from the start
Don't expect the same inner volume from a jacket you'll wear with a thin T-shirt and one you'll wear over a thick knit. Try it on with the layers you plan to wear in daily life. If you need more space, consider a different cut instead of directly going up a size; a larger size might make the shoulders and sleeve length unnecessarily big.
Short checklist during fitting
- Examine the jacket both open and closed.
- Sit down, bend your elbows, and extend your arms forward.
- Check for uncomfortable pressure at the collar and armpits.
- Check the appearance of the back and waist in a mirror.
- Compare the product measurements with your notes.
What should I do if I'm between two sizes?
First, identify where the mismatch is. If the chest fits well but the shoulders are too wide, a different cut might be the solution. Don't choose a jacket that restricts your movement with the thought that "it will loosen up over time"; changes that may occur during use vary depending on the style and material.
To understand the different fits, you can review the leather jacket styles guide. Then, you can narrow down your choice by comparing the product information of the black zip-detail leather jacket with your own measurements.