Sock Knitting Stitch Calculator | Cast-On Counts From Gauge and Foot Circumference
Enter your stockinette gauge and foot circumference, and this calculator works out how many stitches to cast on in the round. Heel, toe and gusset counts sit on the same screen, rounded to a multiple of 4 so they divide evenly across needles.
💡 About this tool
The hardest part of starting a hand-knit sock is the very first number: how many stitches to cast on. A published pattern is fine if your foot and your yarn match the sample, but if your circumference or your gauge differs, the pattern's count comes out too tight or too loose. Doing the maths by hand for every pair gets tedious fast.
This tool takes your foot circumference, applies negative ease (knitting the tube a little smaller than the foot so it hugs once stretched), and multiplies by stitches per centimetre from your gauge. Because sock yarn stretches, the common rule of thumb is about 10% negative ease — multiply the circumference by 0.9. The result is then rounded to the nearest multiple of 4 so the round splits cleanly between instep and sole.
The heel count follows the standard heel-flap (cuff-down) construction, where the flap is worked on half of the cast-on stitches. The toe figure is a guide for the count left before grafting, and the gusset is an estimate of the pickup on each side. All three vary by pattern, so treat them as a starting point rather than a fixed rule.
🧐 Frequently asked questions
Why round the cast-on to a multiple of 4? A sock is knit in the round and split front-to-back, then often across four double-pointed needles. A multiple of 4 divides in half and in quarters cleanly, so the heel and toe counts come out even.
Where do I measure the foot circumference? Wrap the tape around the widest part — usually the ball of the foot, just behind the toes — without pulling tight. Applying roughly 10% negative ease to that number gives the finished circumference the sock should knit up to.
Does this work for toe-up socks too? The total cast-on logic is the same. For toe-up you increase out from a small toe cast-on (often around 14–16 stitches with a Turkish cast-on), so read the "toe stitches" figure as the count you shape toward rather than a literal cast-on.
Should I use my flat gauge or my in-the-round gauge? Ideally your in-the-round gauge. Many knitters get a slightly different gauge knitting in the round versus flat, so a swatch worked in the round gives the closest match.
Does it give row counts or heel turns? No — it reports stitch counts only (cast-on, heel, toe, gusset and stitches per needle). Row counts and decrease rounds depend on your leg and foot length and on the yarn, so they are left out.
📚 Toe-up vs cuff-down: two starting points
Sock knitters split into two camps over where to begin. Cuff-down starts at the leg, casts on the full round, and finishes by grafting the toe closed with Kitchener stitch — the larger cast-on in a loop is generally considered the more beginner-friendly start. Toe-up reverses the order, beginning with a tiny toe (often a Turkish or figure-eight cast-on of around 14–16 stitches) and working up, which lets you try the sock on as you go and stop the leg whenever the yarn runs low. The cast-on number this calculator gives applies to either direction; what changes is whether that count is where you begin or where you end.