Crochet sock size calculator

Socks have to fit snugly without being too tight to pull on. This calculator turns two foot measurements and your gauge into a toe-up sock outline: the stitches around with a little negative ease, the toe increases, how far to work before the heel, and how to split the sole stitches for a short-row heel.

How to use the calculator

1. Stand on paper, mark the back of the heel and the tip of the longest toe, and measure between them.
2. Measure around the ball of the foot, the widest part.
3. Set the ease: about 8% smaller around for socks (5% for thicker slippers), and 5% shorter in length.
4. Enter your stitch and round gauge, from a swatch in the round in your sock stitch.

How the calculator works

Sock circumference = foot circumference × (1 − ease around)

Stitches around = circumference × stitch gauge, rounded to an even number so half go on the instep and half on the sole.

The heel takes about 22% of the foot length, so the foot is worked to:

Foot before the heel = foot length × (1 − length ease) − 0.22 × foot length

The toe starts from a short chain and increases 4 stitches a round (2 at each side) until it reaches the full count. The sole stitches are split into three for a short-row heel, with any remainder in the centre so the sides match.

Reading your results

• Stitches around: with the instep and sole halves.
• Foot length before the heel: with roughly how many rounds from the toe tip.
• Heel split: side / centre / side.
• Toe-up outline: the toe chain, the toe increases, the foot and the heel in order.

Worked example

A 9.6 in foot, 9 in around the ball, at 5 stitches and 5 rounds per inch (20 per 4 in):

• Circumference: 9 × 0.92 = 8.28 in, so 41.4 stitches, rounded to an even 42: 21 instep and 21 sole.
• Toe: chain 6 and work both sides of the chain (10 stitches), then increase 4 a round for 8 rounds to reach 42.
• Foot: 9.6 × 0.95 − 2.11 = 7.01 in from the toe tip, about 35 rounds.
• Heel: work the 21 sole stitches in short rows, 7 / 7 / 7.

Accuracy and limits

• The counts are exact and covered by our automated tests. The heel length (22% of the foot) and ease percentages are design starting points.
• Crochet stretches less than knitting, so crochet socks need less negative ease than knitted ones; very little stretch means the sock may be hard to pull on.
• A high instep may need 2 to 4 extra stitches before the heel.

Common mistakes

1. Swatching flat for a sock worked in the round. Gauge in the round is often different; swatch the way you will work.
2. Too much negative ease. Crochet fabric has less give; if the sock will not pass the heel, add stitches.
3. Measuring the foot sitting down. Feet spread when you stand; measure standing.

Tips for more accurate results

• Stretchy stitches help: extended single crochet, waistcoat stitch or back-loop ribbing.
• Try the sock on as soon as the foot reaches the heel position, and before the heel is closed.
• Use a sock yarn with some nylon for wear on the heel and toe.

Frequently asked questions