Common Jacket Sizing Mistakes

Most jackets that don't fit weren't badly made. They were bought with one of a few predictable mistakes. Here are the ten that come up most, what goes wrong with each, and how to avoid it.

1. Assuming your size is the same in every brand

What goes wrong: you order your usual medium, and it arrives tight across the chest or long in the sleeves. Sizes vary between brands, between countries and even between product lines.

The fix: take your measurements once, save them on your phone, and check them against each brand's own chart every time. Our guide to why jacket sizes differ between brands explains what's going on.

2. Sizing up for layers you never wear

What goes wrong: you picture yourself wearing two jumpers on a freezing day, buy a size up, then spend the winter in a baggy jacket over a single fleece. Ireland's winters are mild and wet far more often than they're bitterly cold, and the extra room makes the jacket colder, not warmer, because warm air escapes every time you move.

The fix: size for the thickest layer you'll really wear most weeks. If you need more room, look for a roomier cut rather than a bigger size. See how much room to leave for layering.

3. Trying on a winter jacket in a T-shirt

What goes wrong: you buy a parka in September while wearing a T-shirt. It fits beautifully. In December you put it on over your usual jumper and it won't zip comfortably.

The fix: wear or bring the layer you'll actually wear under it. If you're buying online, try it at home over that layer before you take the tags off.

4. Ignoring the shoulders

What goes wrong: the chest and length look fine, so you overlook a shoulder seam that sits inside your shoulder or hangs off it. Shoulders are the hardest part of a jacket to alter, so that mistake is close to permanent.

The fix: check the shoulders first. On a tailored or casual jacket, the seam should sit at the bony outer edge of your shoulder, with no dents below it. More in how a jacket should fit at the shoulders, chest and waist.

5. Judging sleeve length with your arms by your sides

What goes wrong: sleeves that look right standing still ride halfway up your forearms the moment you reach for the steering wheel or handlebars. On a rain jacket, that means wet wrists.

The fix: do three tests: arms by your sides, arms reaching forward, and arms overhead. Outdoor jacket sleeves should still cover your wrists when you reach. See are your jacket sleeves too long or too short.

6. Forgetting to check the hood

What goes wrong: the hood is too small to go over a hat or bike helmet, or so big that it falls over your eyes and doesn't turn when you look both ways crossing the road. In a proper Irish downpour, a badly fitting hood is the first thing you notice.

The fix: put the hood up in the shop. Tighten the adjusters, turn your head left and right, and check the peak keeps rain off your face without blocking your view. If you cycle, check whether it's designed to fit over a helmet.

7. Trying it on open

What goes wrong: almost any jacket looks fine unzipped. Once you close it, an X of creases appears across the chest, the collar stands away from your neck, or the zip strains.

The fix: always zip or button the jacket fully before you judge it, including any storm flap over the zip.

8. Standing still in front of the mirror

What goes wrong: you check the fit standing straight, then find the jacket pulls across the back on the bike, rides up when you lift a child into the car seat, or pulls open when you sit down on the bus.

The fix: move. Hug yourself, reach forward, lift both arms overhead and sit down. Copy the movements of your actual day, whether that's a commute, the school run or walking the dog.

9. Ignoring the length

What goes wrong: a short jacket leaves a gap at the small of your back when you bend down, and rain runs straight onto your trousers. A long coat gets in the way on a bike and bunches when you sit.

The fix: decide what length you need before you choose a size. For everyday rain protection, a jacket that covers your backside keeps more of you dry. For cycling, a dropped back hem helps. Check the back length on the size chart against your own.

10. Counting on alterations that aren't possible

What goes wrong: you buy a waterproof or puffer with sleeves a bit too long, planning to have them shortened. Then you find that cutting a waterproof breaks the taped seams, and cutting a puffer means losing fill from the baffles.

The fix: only rely on alterations for tailored jackets and simple casual jackets, where shortening sleeves and taking in the waist are routine. For outdoor and insulated jackets, buy the fit you need and use the cuff tabs and drawcords for fine tuning.

For the whole process from tape measure to checkout, read how to choose a jacket that fits properly.