Measure socks for knitting
Use actual foot circumference and length, then choose the ease and heel construction before calculating stitches.
Circumference
Measure around the ball of the foot without pulling the tape tight. A 22 cm foot with 10% negative ease targets 19.8 cm of relaxed knitted circumference.
Length and calf
Measure heel to longest toe and the desired cuff position. A tube sock has no shaped heel; a fitted heel requires its own heel and gusset instructions and a separate foot-length allowance.
Gauge sample
Measure the intended yarn in the round after washing. Check that the relaxed stitch count stretches comfortably over the heel and returns at the ankle.