Down Fill-Weight vs. Down Fill-Power: Why the Latter Doesn’t Matter

Puffy

How exactly can you shop for a down jacket…and be confident it’s going to be warm enough? Here, we break down one aspect of down jacket selection. Alternatively, check out the insulation we offer for men and women, and email us with your questions.

How much down is in this jacket?

The key question to ask when selecting a down jacket is, “How much down is in that jacket?” This is known as the fill-weight of the jacket. Many brands don’t provide this number, although most can track it down if you call into their customer service lines or speak to gear experts. A jacket listed as having “500 g” of down in it is literally stuffed with 500 grams of down by weight. To put this in perspective, 1400 grams of down is usually sufficient down fill for a -40°F/C sleeping bag.

What most brands do provide, rather than the fill-weight, is the down fill-power. This probably sounds familiar to most: 800-fill, 700-fill, 750-fill…600-fill, 550-fill, etc. These numbers indicate how much “lofting power” the down has. The higher the fill-power, the greater the compressibility and quality of the down used to fill the jacket.

If two jackets were placed side-by-side – one containing 100 grams of 900-fill down and one containing 100 grams of 550-fill down – the jacket with 900-fill-power down would be more packable and warmer than the jacket containing 100 grams of 550-fill down. However, a jacket with 90 grams of 900-fill down will not be nearly as warm as a jacket with 180 grams of 550-fill down. More down = warmer jacket.

How much down for which mountain?

More insulation, or more grams of down, will almost always indicate a warmer jacket. While other factors do make a difference (face fabric, box-baffle vs. sewn-through), total insulation quantity is the most important factor to look at. Before taking a look at our hands-on video comparison of five different jackets, here’s a few general guidelines for fill-weight:

  • Everest. Pack a down suit! We’ve found over the years that a parka-and-pants combination isn’t as ideal on 8848-meter Sagarmatha/Chomolungma.
  • Denali, Mt. Vinson, Aconcagua. 435-525 grams of down – HOOD REQUIRED.
  • Mt. Rainier, Chimorazo, Pico de Orizaba, Kilimanjaro. 200-300 grams of down – HOOD REQUIRED.
  • Mt. Baker, Macchu Picchu, Mt. Shuksan. 130-190 grams of down. HOOD REQUIRED for any summit climbs, hood optional for treks like Macchu Picchu.
  • Midlayer/Extra Insulation/Town. Up to 125 grams of down, vests, hoodless jackets, etc. Use these layers as “add-ons” for your other layers.

 

 

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