You can knit circular projects on straight needles by working back and forth in rows, then seaming the sides together
Knitting in the round on straight needles means you work flat in rows and join the pieces afterward. This is the traditional method—it predates circular needles and double-pointed needles by centuries. You knit a flat rectangle or tube shape, then use a tapestry needle and yarn to close the seam. The result is indistinguishable from a project knit on circular needles if your seaming is neat.
The main trade-off is that you will have a visible seam running up one side of your finished piece. For socks, hats, and sweater bodies, this seam becomes part of the design. For projects where you want no seam at all, circular needles or double-pointed needles are the better choice—but if you only own straight needles, this method works.
Key Takeaways
- Knit a flat rectangle in stockinette stitch (knit on the right side, purl on the wrong side), keeping the edges neat and even.
- Measure your finished piece against the circumference you need—a sock cuff should wrap around your ankle with no stretch, a hat should fit snugly over your head.
- Use a tapestry needle and matching yarn to seam the two short ends together with a mattress stitch, which hides the seam inside the fabric.
- Pick up stitches along the cast-on edge and knit downward to add ribbing, a cuff, or a brim after the main tube is complete.
Calculate the width and length you need before casting on
Measure the circumference of the body part you are knitting for. If you are making a sock, wrap a soft measuring tape around your ankle or the widest part of your foot. If you are making a hat, measure around your head at the widest point. If you are making a sweater body, measure around your chest or waist where the sweater will sit.
Subtract about half an inch to one inch from that measurement—your finished fabric should fit snugly without stretching. This is your target width. Knit a gauge swatch in the stitch pattern you plan to use, measure how many stitches you get per inch, and multiply to find how many stitches to cast on.
For length, measure from the cast-on point to where you want the seam to end. A sock leg is usually four to six inches tall. A hat is usually seven to nine inches from cast-on to crown. Write these numbers down before you start so you do not have to guess halfway through.
Knit a flat rectangle in stockinette stitch with even edges
Cast on your calculated number of stitches. Work in stockinette stitch—knit every row on the right side, purl every row on the wrong side—until your piece reaches the length you measured. Keep your edge stitches (the first and last stitch of every row) loose and even. Tight edges make seaming harder.
A common technique is to slip the first stitch of every row knitwise without knitting it. This creates a chain of loops along both edges that are straightforward to seam later. Bind off all stitches when you reach your target length.
Lay your finished rectangle on a flat surface and measure it. It should be the width and length you planned. If it is too wide or too narrow, you now know to adjust your stitch count for the next project.
Seam the short ends together with mattress stitch
Thread a tapestry needle with a length of yarn that matches your project. Lay your rectangle flat with the right side facing up. Bring the needle up through the first stitch on the left edge, near the cast-on row. Then bring it across to the right edge and up through the first stitch there.
Go back to the left edge and insert the needle under the horizontal bar between the first and second stitch (not through the stitch itself). Pull the yarn through. Cross to the right edge and do the same thing—insert under the bar between the first and second stitch, pull through. Repeat this back-and-forth motion, going under one bar at a time on each side, until you reach the bind-off edge.
Pull the seaming yarn snug every few inches so the edges draw together. When you reach the top, weave the yarn tail through a few stitches on the inside and trim it. The seam should be nearly invisible from the outside.
Add ribbing or a cuff by picking up stitches along the cast-on edge
Once your tube is seamed, you can add a cuff, ribbing, or brim by picking up stitches along the cast-on edge. Hold your circular tube with the cast-on edge facing you. Insert a straight needle through the first cast-on stitch from front to back, wrap yarn around the needle, and pull a new loop through. Repeat along the entire cast-on edge, picking up one stitch in each cast-on stitch.
You now have live stitches on your needle. Knit in ribbing (alternating knit and purl stitches) for one to two inches, then bind off. This ribbing will stretch slightly and hold the cuff snug against your ankle, wrist, or head.
If you are making a hat, you can pick up stitches around the cast-on edge and knit downward to create a brim. If you are making a sock, pick up stitches and knit a cuff. The same technique works for any project where you want to add a finished edge after seaming.
Weave in yarn tails and block your finished piece
After you bind off, thread your yarn tail through a tapestry needle and weave it through the bumps on the back of several stitches. This anchors the tail so it will not unravel. Trim any excess yarn. Do the same with the cast-on tail.
Wet-block your finished piece by soaking it in cool water with a small amount of wool wash (or plain water if you are using acrylic). Gently squeeze out the water, lay the piece flat on a towel in its final shape, and let it dry. Blocking evens out the stitches and helps the seam blend in.
Frequently Asked Questions
Will the seam be visible on the finished project?
Yes, but only as a thin line running up one side. If you use mattress stitch and matching yarn, the seam blends into the fabric and is barely noticeable. Many hand-knit items have visible seams—it is a normal part of the craft. You can position the seam at the back of a hat or the inside of a sock cuff where it is less obvious.
What if I do not have a tapestry needle?
A tapestry needle has a blunt tip and a large eye. You can use a regular sewing needle in a pinch, but the blunt tip of a tapestry needle slides under the yarn loops without splitting them. They cost a few dollars at any craft store and are worth having if you plan to seam projects regularly.
Can I use this method for a sweater body?
Yes. Knit the front and back as separate flat pieces, seam the shoulders together, then pick up stitches around the armholes to knit the sleeves downward. This is how sweaters were made before circular needles became common. It takes longer than knitting in the round, but the result is the same.
What stitch should I use instead of stockinette?
Any stitch that looks the same on both sides works well—garter stitch (knit every row), seed stitch, or ribbing. Avoid stitch patterns that have a clear right and wrong side, like reverse stockinette, because the wrong side will show on the inside of your seam. Test your chosen stitch in a small swatch first.
How tight should I pull the seaming yarn?
Pull snug enough that the edges draw together with no gap, but not so tight that the fabric puckers or the seam becomes stiff. If you pull too hard, the seam will show as a ridge. If you pull too loose, the edges will not close properly. Practice on a scrap piece first to find the right tension.