Down vs. Synthetic jackets: which one should you choose?


Feb 17, 2023

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Down vs. Synthetic jackets: which one should you choose?

If you’re in the market for a new winter coat, you might be wondering whether to go with a down-filled jacket or choose one with a synthetic fill. Undoubtedly, both have their benefits and when crafted to a high standard, will offer excellent protection against the cold.

But which one should you choose? Our handy guide should provide all the details you need to make an informed choice that ticks all the right boxes for your outdoor adventures.

What is a down jacket?

A down-filled jacket is a coat or jacket that uses feathers and down, typically from ducks and geese, as its insulation. The loftiness (otherwise known as the fluffiness) of down is what gives it its unique ability to trap and store pockets of warm air, making it one of the most effective natural insulators out there. When dry, down is also extremely lightweight, meaning it’s an ideal option for things like winter coats and gilets that are often worn over other layers of clothing. Down jackets are usually designed in a puffer or quilted style, as this ensures that the down (and therefore the warmth) is equally distributed throughout the jacket.

The effectiveness, warmth and quality of a down filling will be determined by the fill power, which will range from around 300 to 900. Plenty of laboratory testing goes into determining the fill power of a down jacket, but in simple terms, it is a measure of the down’s ability to bounce back under pressure, which indicates how much air it can trap to keep you warm. The higher the fill power, the warmer and lighter the jacket will be.

Are down jackets waterproof?

Down filling itself is not waterproof, and will become heavier if exposed to moisture. However, many down jackets will come treated with a waterproof coating and will incorporate features like taped seams to prevent moisture from seeping into the jacket and dampening the down.

Generally, down jackets will not provide enough waterproofing to protect against long bouts of heavy rain and are therefore better suited to cold but drier conditions. If your down jacket does become wet, it can also take a while to dry in comparison to a synthetic filling. Many people, therefore, purchase a lightweight, high-fill-power down jacket as a thermal layer which they can easily wear under a waterproof for extra warmth in mixed conditions.

Are down jackets warm?

Down jackets are amongst the warmest jackets you’ll find. Down’s natural ability to trap warmth close to the body and maintain it even in the extreme cold makes it the go-to choice for many people living in colder climates.

How much fill for a down jacket?

The fill power is a great indicator of how warm your down jacket will be, making it easy to find the right option for any temperature. This simple table is a great guide to help you when browsing for the ideal down jacket for you:

  • 300-500 FP – Medium
  • 500-600 FP – Good
  • 600-700 FP – Great
  • 700+ FP - Excellent

Keep in mind that the higher the fill power, the better the quality of the down will be. Better quality down will be more efficient at trapping warm air pockets, meaning less of it will need to be used. For this reason, a higher fill power will also equate to a lighter jacket that is easier to pack down and store.

What is a synthetic-filled jacket?

As the name suggests, a synthetic-filled jacket uses synthesised materials instead of down for insulation. Synthetic insulation is typically made with polyester or recycled plastics and is designed to provide warmth just like a down jacket. They are also often styled in a similar way to down jackets with a quilted pattern, making them a great alternative for those seeking a sustainable or ‘greener’ winter jacket that doesn’t use animal products.

Synthetic-filled jackets aren’t measured for warmth in the same way as down, so will not offer a fill power rating that you’d see on down-filled coats. As it lacks the true loftiness of down, the synthetic filling tends to be slightly heavier and bulkier than down filling, however, there are plenty of lightweight options available.

Are synthetic jackets waterproof?

Similarly to down jackets, synthetic jackets vary in quality, so it is important to be on the lookout for details such as waterproofing, weatherproofing and wind protection. You should also look for features like taped seams to ensure that your jacket insulation remains dry.

Synthetic insulation will dry far easier than down, so there is a little less risk when wearing these jackets out in the rain. Down also will get very cold when wet, whereas synthetic filling can stay warm even if it gets damp. For this reason, synthetic-filled winter coats are great for climates that have a little more rain in winter.

Are synthetic jackets warm?

Synthetic jackets can be extremely warm, depending on the make and quality. Synthetic filling is often modelled on down filling, using materials and construction techniques to mimic down as closely as possible. While the warmth factor can resemble down, synthetic jackets tend to be a little heavier, so this is something to bear in mind if you’re layering up.


So which jacket should you choose?

Ultimately, there are many pros to both down-filled and synthetic jackets. Depending on your lifestyle, ethos, and budget, you’ll find plenty of options for either type of jacket to suit your outdoor adventures. Down is fantastic for colder, drier conditions and has plenty of variety when it comes to warmth, however, it does tend to be slightly more expensive than synthetic fabric and isn’t great in heavy rain. Meanwhile, synthetic jackets are a great option if you’re thinking about sustainability, as many of these coats are made with recycled materials. While a little heavier than down, they tend to be slightly more affordable and can last longer in wet conditions.

Whatever you choose for your next winter coat, you can find a great range of down-filled and synthetic jackets and gilets right here at TOG24.

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