Down Jacket Fit Guide: How to Choose the Right Size

The Short Answer

Choose a down jacket that fits close but never tight. You need enough room for a mid layer underneath, full arm movement, and a hem that does not ride up when you raise your arms. Between two sizes, always size up.

A proper fit is what separates a jacket that feels premium from one that feels off, so it is worth getting right before you buy.

Start With the Layering Test

Most down jackets are designed to be worn over a base layer and a mid layer — not directly on bare skin.

Put on the jacket over a light sweater and zip it fully. Then check two things:

• You can move your arms freely in every direction
• You can button or zip comfortably without the fabric pulling across the chest

If the jacket feels snug over a sweater, it is too small — you will end up layering it over thinner tops all winter.

Sleeve Length: The Wrist Rule

Sleeves should end at the wrist bone, with the cuff just covering the base of your hand.

Raise your arms to shoulder height: the sleeve should stay comfortably in place, not slide up several inches. That sliding is a classic sign of a too-short sleeve, and cold air will find its way in on windy days.

Shoulders and Chest: The Seam Test

Look for the shoulder seam while you are wearing the jacket. It should sit right at the edge of your shoulder, not drooping down your arm and not digging into your neck.

Across the chest, the jacket should follow your body without pulling. If you see fabric strain or feel tightness when you cross your arms, go up a size.

Body Length: Hip vs Waist

Length is a matter of use, not just preference:

• Short styles end around the waist and are ideal for driving, climbing and active wear
• Mid-length styles cover the hips and seal out cold air around the lower back
• Long styles extend past the hips and offer maximum coverage for sub-zero commutes

If you plan to wear the jacket outdoors in deep winter, choose a length that covers your hips — that is where a surprising amount of heat escapes.

If You Are Between Sizes, Size Up

Down jackets run slightly roomy by design, because the loft needs space to expand and trap air. If you are between two sizes, the larger one is almost always the right choice: it keeps the loft working and leaves room for layering.

A Quick Reference for US Sizing

As a general guide for men's outerwear (always check the brand's own size chart, and note that women's sizing runs differently):

• XS: chest 32-34 in (81-86 cm)
• S: chest 34-36 in (86-91 cm)
• M: chest 38-40 in (96-101 cm)
• L: chest 42-44 in (106-112 cm)
• XL: chest 46-48 in (116-122 cm)

These ranges vary between brands. What matters most is the layering test above — fit for a sweater, not for bare skin.

The Bottom Line

A well-fitted down jacket is close but never tight, layered-friendly, and long enough for how you will actually wear it. When in doubt, size up — the loft needs room to work.

At MYCOAT, our jackets are cut for a clean, alpine-inspired fit with room to layer comfortably, filled with 90/10 European white goose down at 700+ fill power. If you are between sizes and unsure, contact us and we will help you choose.

Shipping cost is not included — contact us for a quote.