How to Knit Toe-Up Socks Using Judy's Magic Cast On

Toe-up socks are exactly what they sound like: you start at the tip of the toe and work upward to the cuff. This approach has real advantages — you can try the sock on as you go, you use every last metre of yarn before casting off, and you can adjust the leg length at the very end rather than at the beginning. The one thing that stops knitters is the cast on: how do you start knitting in the round from a point with no existing stitches?

The answer is Judy's Magic Cast On, invented by Judy Becker and published in Knitty in 2006. It simultaneously casts stitches onto two needle tips pointed in opposite directions — giving you a seamless starting row with live stitches on both sides, exactly what a sock toe needs.

What You Need

Two circular needle tips (or two circular needles) in your sock needle size — typically 2–2.5mm for fingering weight

Sock yarn

A loose slipknot's worth of yarn (don't make an actual knot — just a loop to start)

Magic loop technique works well for toe-up socks: one long circular (80–100cm) gives you the equivalent of two needle tips. If you prefer DPNs, Judy's Magic Cast On works with those too — you just distribute the stitches immediately after casting on.

How to Work Judy's Magic Cast On

This cast on will give you stitches on two needles simultaneously. The number you cast on depends on your pattern — a typical start is 8 stitches total (4 per needle), or 12 stitches total (6 per needle) for a wider foot.

Hold your two needle tips parallel, both pointing to the right. The yarn tail hangs between them in the centre.

Hold the yarn so the tail goes over your thumb and the working yarn (attached to the ball) goes over your index finger. You're essentially making a slingshot shape with your left hand.

Bring the bottom needle tip (needle 2) toward you under the thumb loop, then up and over to catch the thumb yarn and pull it through — this puts one stitch on the bottom needle. Pull the tail snug.

Now bring the top needle tip (needle 1) away from you, up and over the index finger loop, and pull through — this puts one stitch on the top needle. Pull the working yarn snug.

Alternate: one stitch on the bottom needle (thumb), one on the top needle (index finger). Continue until you have your target number of stitches split evenly between both needles.

Gently separate the needles so the two sets of stitches face each other on their respective tips.

The cast on can feel awkward at first — even very experienced knitters feel like they're doing it wrong until suddenly it works. The stitches should spiral slightly around the needle tips with a neat line of twisted yarn at the very tip of the toe. If your stitches are all twisted in the same direction when you look at the cast on line, you're doing it correctly.

Knitting the First Round

This is the part that confuses nearly everyone the first time, so go slowly.

The stitches on the top needle need to be knitted through the back loop on the first round only — this untwists them. Every stitch on needle 1 (the first needle you'll knit): knit through the back loop (ktbl).

Turn the work. Now needle 2's stitches become the active needle. Knit across these stitches normally (through the front loop).

You've now worked one round. Your cast on row is complete. All subsequent rounds are worked normally — no more back loop knitting.

Working the Toe Increases

After the first round, you start increasing to widen the toe. Most sock patterns use 4 increases every other round (two per needle, one at each end). The standard increase sequence:

Increase round: K1, M1L, knit to last stitch of needle 1, M1R, K1. Repeat for needle 2.

Plain round: Knit all stitches with no increases.

Alternate between increase rounds and plain rounds. M1L (make one left) and M1R (make one right) lean in opposite directions, which creates a neat, symmetrical increase line along the sides of the toe. Other increase types (KFB, yarn over) also work but create a different visual effect.

Continue until you have the stitch count the pattern specifies for the foot — typically 60–72 stitches for an average adult foot in fingering weight. This usually takes 12–16 increase rounds, depending on your starting stitch count.

From Toe to Heel: Working the Foot

Once your toe increases are complete, you work the foot plain — just knitting in the round — until you reach the heel position. Measure the foot length from the tip of the longest toe (try it on if you can, or measure against the recipient's foot if it's a gift).

Stop knitting the foot when you're about 5–6cm shorter than the total foot length. This leaves room for the heel plus the very short transition from the top of the heel to the ankle.

For toe-up socks, German short-row heels and afterthought heels both work seamlessly. See the heel methods comparison guide for detail on each.

The Advantages of Toe-Up Construction

Once you're comfortable with Judy's Magic Cast On, toe-up socks have several genuine advantages over top-down construction:

Try as you go: Slip the work-in-progress onto your foot at any point to check the toe shape, the foot length, and the heel fit before you commit.

Use all your yarn: Knit the leg until you have just enough yarn left for the cast off. No guessing how to divide a skein between two socks.

No grafting required at the toe: The cast on creates a closed toe naturally. You can eliminate Kitchener stitch entirely if you dislike it.

Adjustable leg length: You decide how long the leg is when you get there, not when you cast on.

Common Mistakes and How to Avoid Them

The stitches on the first round are all twisted: If you forgot to ktbl on needle 1's first round, the stitches will sit twisted on the needle. Tink (unknit) back to the start of the round and redo it with ktbl for the first needle only.

The toe has a hole at the centre tip: This usually means the first round wasn't worked correctly, or the cast on stitches were too loose. The fix: pull the yarn tail gently after the first round to close up any gap, then weave it in tightly on the inside.

Increases are leaning the wrong way: Double-check that you're working M1L and M1R in the right positions. M1L (lift the bar from front to back, knit through back leg) at the start of each needle; M1R (lift the bar from back to front, knit through front leg) at the end of each needle.

Getting tangled up in your toe? Emma can walk you through it step by step →