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Darn Tough RFL Over-the-Calf Ultra-light Review

Darn Tough RFL Over-the-Calf Ultra-light
RFL Over-the-Calf Ultra-Light
Credit: Darn Tough
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Price:  $24 List | $17.40 at Amazon
Compare prices at 3 resellers
Pros:  Wick moisture well, warm when wet, lifetime guarantee, stylie
Cons:  Not a cozy feel, constricting for larger volume feet
Manufacturer:   Darn Tough
By Chris McNamara ⋅ Founder and Editor-in-Chief  ⋅  Oct 6, 2017
Our Editors independently research, test, and rate the best products. We only make money if you purchase a product through our links, and we never accept free products from manufacturers. Learn more
  • Comfort - 30% 7.0
  • Warmth - 20% 9.0
  • Drying Speed - 20% 9.0
  • Fit - 20% 9.0
  • Durability - 10% 7.0

Our Verdict

The Darn Tough RFL Over-the-Calf Ultra-light is made to perform in a whole range of conditions: Sun or sleet, corduroy or powder, these socks are ready to take it on. For skiers who demand a tight fitting boot and cannot compromise on thickness in their ski socks, Darn Tough Over-the-Calf Ultra-light ski sock is the answer. We found the Darn Tough to be snug if even tight fitting, but thought it was lacking in the cozy feeling we got from socks like the SmartWool PhD Ski Medium.

That being said, when high output is required, the Darn Tough is vey efficient at staying warm, even when things became wet. If you're looking for a high performance quiver sock, not just something that makes you feel good, the Darn Tough Over-the-Calf Ultralight is a great choice.

Our Analysis and Test Results

Tested up against the best ski socks on the market, the Darn Tough Over-the-Calf Ultralight created its own demand. With the highest warmth-to-weight ratio and a lifetime guarantee, these socks make a great choice for anyone who is of the notion that the thinner the sock, the better.

Darn Tough RFL Over-the-Calf Ultra-light ski socks - the darn tough over-the-calf ultralight keeping things warm and dry...
The Darn Tough Over-the-Calf Ultralight keeping things warm and dry deep into the afternoon, when we just could not get enough!!!!!!
Credit: Dustin Simoens


If you're buying socks for their cozy factor, these socks are not for you. Comfort in these socks comes from a lack of padding to allow you foot to sneak into performance fitting boots. Compared to the all other socks tested, they feel very thin. Some testers found these socks, like the Icebreaker, to be constricting around the foot, which resulted in cold feet.

Darn Tough RFL Over-the-Calf Ultra-light ski socks - darn tough over-the-calf ultralight, the tallest and thinnest socks...
Darn Tough Over-the-Calf Ultralight, the tallest and thinnest socks in our test.
Credit: Kristen Shelburg


The Darn Tough Over-the-Calf Ultralight is the warmest sock we tested for its weight. Despite the thin construction of these socks, they are very warm even when things get wet. Though these socks do perform well, they are not warm in the sense of cozy, and if that is of importance, the SmartWool PhD Ski Medium would make a better choice.

Wicking Ability & Drying Speed

Wicking moisture is what these socks do best. They are built with a high concentration of merino wool, and they compare similarly to the PhD in their performance. If this is the single most important factor in your decision making, the Icebreaker Ski+ Light is the best sock for you.

Ski Boot Fit

The Darn Tough Ultralight is set apart from the field in this category. With no padding in the foot and very little on the shin, this sock is made for a specific skier. While the SmartWool PhD will be better for a more loose and comfortable ski boot, the Darn Tough is ready to fit into the tightest ski boots out there.

Darn Tough RFL Over-the-Calf Ultra-light ski socks - the icebreaker ski+ lite (left) compared with the taller and thinner...
The Icebreaker Ski+ Lite (left) compared with the taller and thinner Darn Tough Over-the-Calf Ultralight (right). The Icebreaker model wins for best wicking capability.
Credit: Kristen Shelburg


Despite the thin nature of these socks, we were surprised at how quickly these socks began to deteriorate. We found them to get stiff under the balls of the foot after a single use, and could not get them to soften up after washing. Look to the SmartWool PhD if durability cannot be compromised.

Best Applications

These socks are made to perform. We found them to be best used as a quiver sock, when compromises in fit and performance cannot be made. Use this thin sock when you break out your performance boots, and wear a thicker, more plush sock on a casual day in looser boots.


At $24, these socks are not cheap. However, for skiers who demand that quiver sock, this is a great option, and with a lifetime guarantee you can continue to return socks that fail to meet your satisfaction.


Though there are many better options for the everyday skier, this sock is made for someone who knows exactly what they want. Darn Tough has delivered a quality product, and continues to maintain its position in the high end sock world.

Chris McNamara
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