Merino vs synthetic hiking socks

What merino does well

Merino is a fine wool from merino sheep. Its fibres are thin enough that most people find it soft rather than itchy. It holds warmth even when damp, which matters in a boot that has taken on water or in cold, wet weather. It also tends to resist odour, so many walkers can wear merino socks for more than one day on a trip.

The downsides are durability and drying time. Pure merino wears through faster at the heel and toe, and it takes longer to dry than synthetic fibres. That is why most merino hiking socks include nylon and a little elastane.

What synthetic socks do well

Synthetic hiking socks use nylon, polyester, polypropylene or branded fibres such as Coolmax. They move moisture away from the skin, dry quickly and are hard-wearing. They suit hot weather, fast walking and trips where you wash socks each evening and need them dry by morning.

Their main weakness is odour, which builds up faster than in wool. Some brands add treatments to reduce it. Synthetic socks also feel less warm once wet.

Merino, synthetic and blends compared

The table shows general traits. Knit, thickness and cushioning affect performance as much as fibre, so treat it as a guide.

Why cotton socks are bad for hiking

Cotton absorbs sweat and holds it against the skin. Wet cotton loses most of its warmth, stays wet for a long time and becomes softer and more prone to rubbing. That combination is why walkers and mountain leaders recommend leaving cotton socks at home for hill days.

For a short walk on a dry day, cotton will not ruin anything. For longer walks, wet weather or cold conditions, a wool or synthetic sock is more comfortable.

Note:Wet, cold feet can become a real problem on long winter days. Carry a spare pair of socks in a dry bag on the hills.

Which to choose

For most British walking, a merino-rich blend with nylon reinforcement is the safest all-round choice. It stays comfortable in wet weather, copes with multi-day use and lasts reasonably well. In summer heat or for fast walking, a lighter synthetic or low-merino sock dries faster and feels cooler. For winter, a thicker merino-rich sock adds warmth, as long as your boots still fit with it.

Our guide to hiking socks for summer and winter covers thickness by season, and hiking socks explained covers cushioning and fit.

• All-round UK walking: merino blend with nylon.
• Hot weather and fast walking: light synthetic or low-merino blend.
• Cold winter days: heavier merino blend, checked against boot fit.
• Multi-day trips: merino blend for odour resistance.

Socks and boot fit

Whatever the fibre, try boots on with the socks you plan to wear. Switching from a thin synthetic sock to a thick merino one can make a boot feel half a size smaller. If you are buying new boots, bring both your summer and winter socks to the fitting.

Our guides to the best waterproof walking boots for men and for women note which models have roomier lasts that take thicker socks.

See waterproof walking boots for women →

Frequently asked questions

Do I need merino wool socks for hiking? Not necessarily, but they are a good choice for cold, wet and multi-day walks. Synthetic socks work well in summer.

Is merino worth it? For many walkers, yes, because of comfort and odour resistance. Blends with nylon last longer than pure merino.

Do merino socks itch? Fine merino is usually soft. If wool irritates your skin, try a synthetic sock or a thin synthetic liner under the merino sock.

How should I wash merino socks? Inside out on a cool wool cycle without fabric softener, then air dry. Our guide on how to wash hiking socks has the details.