What is Down Fill Power? Puffy Jacket Ratings Explained
Down fill power, numbers like 650 or 900+, refer to the quality of the insulation in puffy down jackets (or pants). What does this mean for you? It means that not all down jackets are created equal: there are options ranging from lightweight down vests, to packable hoodies, to giant down parkas fit for arctic expeditions. Once you understand what down fill power ratings mean, you'll be better equipped to choose the right jacket for your next adventure.
In this article, the Burton outerwear designers break it all down, explaining what down fill power is, how it's measured, what numbers you should choose when purchasing a down jacket, and how to take care of your down jacket including patching and washing it.
What is down fill power?
Down fill power is a number that describes the quality of down insulation found in jackets, snow pants, and other insulated outerwear. This number may be written in a few different formats like “650fp”, “650 fill", or "650 power fill". These three examples all mean the same thing.
Down fill power is a measurement of the volume that one ounce of down (28 grams) occupies in a cylinder after being compressed by a standardized weight for one minute. For example, 500 fill power means that a sample of down maintained 500 cubic inches of volume after being compressed for one minute. Ultimately, higher the down fill power ratings indicate that more air is trapped between the individual down fibers. High quality down jackets generally have fills ranging from 650 to 1000, but those numbers alone don’t tell you how warm a jacket is, in practical terms. The warmth of a down jacket is ultimately determined by the total volume of down it contains. Here's a simple math equation you can use to figure this out.
Down Fill Power x Down Fill Weight = Total Volume of Down
Note that a jacket's construction also factors into its warmth, but that is outside the scope of this article. Read PrimaLoft vs. Down to learn about sewn-through and boxed baffle construction and how these sewing construction techniques affect warmth.
Pro tip: Watch down fill power being measured to better understand how fill power ratings are calculated.
How do you compare the warmth of down jackets with different fill power ratings?
It's important to understand how to compare the warmth of two different down jackets when shopping for a new one. Why? Because it's common for the jackets you are considering to have slightly different down fill power ratings, and this doesn't allow you to compare apple to apples, as they say. The good news is that doing some very simple math will allow you understand where they all fall in terms of approximate warmth. We say approximate warmth because there are additional factors beyond down fill power that determine a jacket's warmth, but more on that later.
First, let's work through two examples that illustrate how to compare the warmth of down jackets with different fill power ratings.
Example 1
- Jacket A has 2 ounces of 500 fill power down (2 ounces of down x 500 cubic inches = 1000 cubic inches)
- Jacket B has 1 ounce of 1000 fill power down (1 ounce of down x 1000 cubic inches =1000 cubic inches)
Example one shows us that two jackets with very different qualities of down fill can effectively have the same overall volume of insulation. This ultimately makes them equal in terms of their ability to insulate, however as we mentioned above, construction is a factor too. Note that if two jackets advertise their down fill volume using different units, like ounces and grams, you will have to convert one of the weights before doing the comparison.
Example 2
- Jacket A has 4 ounces of 650 fill power down (4 ounces of down x 650 cubic inches = 2600 cubic inches)
- Jacket B has 56 grams of 1000 fill power down (First convert: 28 grams = 1 ounce, so 56 grams / 28 = 2 ounces. Now calculate volume: 2 ounces of down x 1000 cubic inches = 2000 cubic inches)
Example two was a little more complicated because it involved a conversion. In example two, Jacket A will feel warmer because it has a higher overall volume of down than Jacket B, even though it uses lower fill power down.
What down fill power rating is best?
Now that you understand how down fill power is measured, you can start narrowing in on the fill rating that is best suited for your individual needs. There are many different options, from 500 fill power vests to 700 fill power anoraks to big 950+ fill power hooded parkas. The most important thing to understand at this point is that a higher fill power rating isn't automatically better. Below is a quick breakdown of the key qualities associated with higher and lower fill power ratings.
- Higher Fill Power: More compressible, lighter, more expensive.
- Lower Fill Power: Less compressible, heavier, more affordable.
With these qualities in mind, continue reading to identify the situation which you most closely identify with. Let this information help guide your choice.
I Need a Versatile Down Jacket that Can Adapt to a Variety of Temperatures
If versatility is most important to you, Burton's experts recommend utilizing a lightweight, high fill power down jacket as part of a layering system. Higher fill power can deliver warmth without bulk, as long as you choose a jacket that isn't massive. One option that fits this need very well is the [ak] Baker Down Jacket, an 800 fill power, packable down jacket that layers well due to low weight and bulk. Lightweight, high fill power down jackets like the Baker pack down very small, perfect for stashing in a backcountry backpack. Lightweight down jackets should be paired with a base layer for optimal comfort. Make sure to throw a waterproof shell over the top if there's any chance of precipitation, so your down stays dry.
I Need the Warmest Down Jacket that Exists
If you need the warmest down jacket available, for mid-winter dog walks, belaying your friend on an ice climb, or for use on extended backcountry trips and expeditions, a parka-style down jacket with a high volume of down fill AND high fill power is the best choice. The Burton [ak] Baker Expedition Down Jacket is a great example, featuring 800 fill power down, and lots of it. Down parkas generally have large hoods and may feature dropped hems that provides fuller coverage for your upper thighs and booty. Whether you plan to use your parka in an urban or backcountry setting, make sure to consider sizing, as you will likely want enough room to wear it over other bulky layers like a sweatshirt or fleece, or even toss it on over your shell if you're sitting around in sub-zero conditions.
I Need an Affordable Down Jacket that Doesn't Cost Too Much
If affordability is a top concern for you, don't worry, there are still lots of options on the table. One of the easiest ways to save some cash when shopping for a budget-friendly down jacket is to look at options with lower fill power ratings, something in the 600-700 range. Lower fill power ratings can still deliver lots of warmth, they will likely just be a little less compressible and a bit heavier than their higher fill power counterparts. If the price of down still feels out of reach, consider synthetic insulation which may be a more affordable alternative. While synthetic jackets may not have that puffy down jacket aesthetic, they will certainly still deliver on function. When all else fails, consider shopping at a local outdoor gear reseller in your area. This is often the best way to get really high-quality pieces of gear for a steal.
I Need a Down Jacket for Use in Cold, Wet Conditions
If you reside or recreate in cold, wet locations, like the Pacific Northwest of the United States, a synthetic insulated jacket may actually be a better choice than a down jacket. Unlike down insulation, which clumps together and looses its ability to keep you warm when it gets wet, synthetic insulation keeps working. Look for jackets with Primaloft®synthetic insulation, or Burton Thermacore synthetic insulation. High-performance synthetic jackets like the [ak] Helium Stretch Insulated jacket are easy to care for at home, will keep you warm even when damp, and are great alternatives to down.
Pro tip: Regardless of aesthetics, it’s important to have a properly sized down jacket since down will not perform efficiently if the garment is too tight or overly baggy. Reference our snowboard jacket sizing guide to understand Burton’s range of jacket fits.
How do I take care of my down jacket?
You did your research and purchased the down jacket of your frigid winter dreams, so now what? Properly storing and caring for your down jacket ensures that it will deliver comfort and warmth for many seasons to come.
Despite what you may have heard, taking care of down jackets is relatively easy with a few key tips from the outerwear experts at Burton.
- Hang down jackets on a clothes hanger or store them loosely in a large cotton stuff sack when not in use. NEVER store down jackets compressed.
- Wash your down gear at least once per season, more if used frequently.
- Cover holes or tears with a gear patch (or duct tape) to prevent down loss.
Properly Storing Down Jackets
One of the best ways to extend the life of your down jacket is to get into the practice of properly storing it during the offseason. Remember, the primary way that down keeps you warm is by trapping warm air in between layers of fluff. Careless storage of down jackets can result in compression of the down fill, which ultimately leads to reduction in performance and a shorter lifespan of your jacket.
To store your down jacket during the off-season, follow these easy steps.
- Empty all the pockets and give the zippers a quick cleaning with an old toothbrush and some soapy water. Pat dry with a clean rag.
- Wash and thoroughly dry your down jacket, based on the manufacturer’s cleaning recommendations.
- Once completely dry, hang the down jacket on a clothes hanger or loosely place it in a cotton storage bag in a dry location. Never store down jackets in a compressed state for extended periods of time.
Washing Down Jackets
Over the course of the season, your down jacket will inevitably get dirty. Whether it’s a coffee spill on the drive up to the mountain or a nasty oil drip from the chairlift tower (yes, we have all experienced this), washing down outerwear is quick and simple.
- Use a reliable down-specific detergent like Grangers Down Wash.
- Use a front-loading washing machine (or your kitchen sink and hands), to wash your down jacket. Make sure to reference the care label on the garment for water temperature and washer settings.
- Dry your down jacket according to the care label. Add three clean tennis balls into the dryer with your jacket to help break up the damp clumps of down so that they can dry completely and fully re-loft. It is likely that you will need 2-3 dryer cycles to get your jacket completely dry and re-lofted.
Review How to Wash a Down Jacket for more detailed instructions on how to clean different types of down outerwear.
Repairing Down Jackets
If you use your gear as hard as we do, there is a good chance that it might get damaged at some point. If you get a hole in your down jacket, you should immediately cover it with tape (duct or packing can work in a pinch) to prevent the down fill from escaping. Once you return home from your adventure, remove the tape, clean the hole using 70% isopropyl alcohol (stronger solutions may cause damage to fabric and are not recommended), and install a gear patch. Review our guide to patching down jackets for step-by-step instructions on this process.
If you notice small feathers poking out through the outer fabric of your down jacket, don’t pull them out. This will only enlarge those little holes, making it easier for other feathers to poke through too. Instead of pulling feathers out, grasp the feather from behind the fabric, and pull it back inside the jacket. Once the feather is no longer sticking out, massage the fabric where it was poking through so the individual fabric fibers can “heal”, and other feathers can’t escape.
Pro tip: Holes that develop in jackets due to normal wear and tear are not covered by the Burton Warranty. If you've got a hole that needs fixin', but you'd rather let the pros handle the repair, reach out to the Burton Guides. Be aware that sending your jacket in for a professional repair may incur a fee.
Burton’s Commitment to Sustainable and Ethical Down
Because down is an animal product, we strongly suggest only purchasing garments that adhere to ethical sourcing practices. Burton is proud to report that we only source down from responsibly certified suppliers that do not allow for live plucking and which also ensure that animals in their supply chains are not exposed to unnecessary harm.
As a personal best practice, we encourage you to keep your down garments in functional working condition for as long as possible and resist the urge to replace them simply for cosmetic reasons. Give these animal-derived resources the respect that they deserve with proper care for a long and functional life.
Down or Synthetic Insulation
Remember that down is not the only insulation option available for cold weather activities. Synthetic insulation, like Primaloft and Burton Thermacore, are both viable alternatives to down. Synthetic insulations are not generally as compressible or lightweight as high-quality down, but what they lack in packability they make up for in other areas.
