Mountain Equipment Mens Superflux Jacket Medieval Blue

How Should Your Insulated Jacket Fit?

Insulated jackets are pedantic little things. Too tight and you'll compress the insulation and limit the warmth capabilities of your brand new jacket, too loose and you'll spend hours warming up the dead space inside the jacket. Getting the correct fit isn't just about aesthetics, it will determine how warm you are. 

The Incorrect Fit
Too loose: A jacket which is too loose will keep you relatively warm, however it will take far longer to do so and will waste large amounts of your precious energy. An insulated jacket works by trapping the natural heat that your body gives off in the fibres of the insulation; this creates a micro-climate inside your jacket, keeping you warm and toasty. If your jacket is too loose, heat will be able to escape through the hem, the sleeves and the neck of the jacket; it's a little like sticking the heating on in your car with the windows cracked open - it will heat up, just incredibly slowly.   

Too tight: A jacket which is too tight is arguably worse than one that is too loose. If your jacket is far too tight, the baffles can compress to a point where the insulation can't loft effectively, limiting the amount of warmth it can trap. Essentially, it won't work! 

The Correct Fit
It's a tricky one to explain, but it's somewhere in the middle. You've first got to consider how many layers you'll tend to wear underneath; will you have just a t-shirt then the jacket, or possibly a baselayer, midlayer and then the jacket? When you've figured out your layers and you've popped your insulated jacket over the top, you shouldn't have any dead space inside. The cuffs and hem should be comfortably sealed around your waist and wrists with room to move. You should be able to lift an arm up above your head without the hem of the jacket lifting more than an inch or so, and the sleeves should be long enough that when carrying out the same motion, they aren't mid-way up your forearm. Your shoulders and chest area should have enough room so that your hands can touch behind your back without feeling restricted. 

Additional Information
Lastly, consider which activites you'll primarily be carrying out while wearing the jacket. Are you primarily using it as a winter climbing piece, or an everyday/dog walking jacket? You'll find that technical climbing jackets tend to feature a shorter cut, while urban and casual jackets feature a longer cut to offer additional warmth with less mobility.

To see examples of what a badly fitting and correctly fitting jacket looks like, click here.