What they share
Same men’s/unisex chart, same micro crew name, same 8.5-inch average height from heel to cuff. Your size carries over from one to the other.
Where the padding differs
The Hiker is midweight with cushion underfoot. The Light Hiker is a lightweight knit with cushioning underfoot, atop the ankle and up the Achilles. A lighter knit takes less room in the shoe.
The blends differ too
The Hiker 1466 is 61% merino, 36% nylon and 3% Lycra. The Light Hiker 1972 is 43% merino, 54% nylon and 3% Lycra. More merino in the Hiker, more nylon in the Light Hiker.
Which to choose
Roomy boots, cooler days, long days on hard ground: the Hiker. Trail runners, low hikers, snug boots and hot days: the Light Hiker. Darn Tough also makes the Light Hiker as a quarter and no-show if you want it lower.
Women’s versions are separate socks
The women’s Hiker 1903 and Light Hiker 1967 use the women’s chart and a 7.5-inch cuff, and the women’s Hiker has its own blend. Compare them with each other, not with the men’s.
What a published review found
OutdoorGearLab’s October 2022 review of the Light Hiker Micro Crew used the same 54% nylon, 43% merino and 3% Lycra blend, but names no style code. Its notes are on the Light Hiker profile; this guide has not tested either sock.