What does co mean in knitting?

How to work it

co means cast on: putting the first stitches on the needle, before the first row. Every knitted piece starts with it, and the cast-on forms the bottom edge of the work.

The long-tail cast-on is the most common: leave a tail about three times the width of the piece, make a slip knot on the needle, and with the tail over your thumb and the working yarn over your index finger, take one loop from each to form each new stitch.

Patterns name the method when it matters: a cable cast-on for a firm edge, a provisional cast-on when the stitches will be picked up again later.

In a pattern

CO 40 sts. Work in k1, p1 rib for 6 rows.

“CO 40 sts. Work in k1, p1 rib for 6 rows.” means: cast on 40 stitches, then work a rib of one knit stitch and one purl stitch, alternating, for six rows. Count your stitches after casting on: forty, no more and no fewer, or the rib will not line up.

US or UK?

CO means cast on in both American and British patterns. French patterns write “monter les mailles”, often “monter 40 m.”. Crochet doesn’t use these letters: a crochet piece starts with a chain (ch).

Common mistakes

• Casting on too tightly. The edge doesn’t stretch and puckers: cast on over two needles held together, or with a needle one size up.
• Running out of tail with the long-tail method. Leave more than you think, about 2.5 cm of tail per stitch for a medium-weight yarn.

A tip

Put a marker every 10 or 20 stitches while casting on: counting forty stitches in groups of ten is quicker and safer than counting them in one go.

Frequently asked questions

Does the cast-on count as a row?

Usually not: the first row is the one you knit after casting on. Some patterns do count it; their row numbering tells you.

Which cast-on should I use?

The one the pattern names. Otherwise, the long-tail cast-on suits most pieces.

See also

• bo — bind off
• m1 — make one stitch
• tbl — through the back loop
• ssk — slip slip knit

Go further

• Guide: how to read a crochet or knitting pattern