The sock twists around your foot
Short answer: A sock that twists is too big or has lost its shape. Choose the size by foot length and look for a heel that is actually knitted as a heel.
A sock needs a heel
A tube sock with no shaped heel can do nothing but twist. A sock with a real heel shape stays put because it locks around the angle of the heel. You notice it as you pull the sock on and feel it drop into place.
Size matters most
Two sizes too large means folded fabric under the foot and a sock that wanders. Sock sizes often span two shoe sizes, and if you sit on the border, go by foot length rather than by the shoe. See bamboo socks for women.
Wear makes it worse
After many washes a sock loses some of its shape. You notice the twisting first and the rolling leg later. Washing hot gets you there faster. See all bamboo socks for women.
Shoe and sock have to match
A smooth lining, a loose heel counter or a shoe that is too big will make the sock twist whatever the quality. Try thin insoles before you change sock type. See bamboo tennis socks for women.
Frequently asked questions
Does washing hotter help
No, quite the opposite. Heat weakens the elastic that is meant to hold the shape.
Is a sock without a heel always poor
Not always, but it needs a tighter knit and the right size to stay in place.
Why does the sock twist most in summer
Because moisture from sweat makes the fabric slide more easily against the skin.