When knitting with circular needles, the key thing to remember is that you are always working from the right side, or what will be the outside of the work when it is worn or used. What would be the wrong side rows if you were working flat are just every other right side round when knitting circularly.
Backward and Opposite
Since the knit stitch and the purl stitch are opposites, to get these “wrong side” rounds to look right on the right side, you have to work stitches the opposite of what you would in flat knitting. The classic example is the stockinette stitch, which is worked flat by knitting a row and purling a row. In circular knitting, instead of purling that row, you’re knitting a round—the opposite of what you’d do knitting flat. Likewise, with garter stitch, which is knit every row when worked flat, you have to purl the second round in order to get the classic corrugated look. With more complicated stitch patterns you have to think a little bit more about what you’re doing when you convert flat stitch patterns to circular knitting, but it’s not too difficult. The rounds that would have been wrong side rows are both opposite and backward from the way you’d knit them flat. It’s easy to visualize that if you think about something like a knit 3, purl 1 rib. Worked on a multiple of 4 stitches, you’ll end with a purl 1. When you work the wrong side, you’ll knit 1, purl 3 across. In circular knitting, you just keep repeating the knit 3, purl 1—opposite and backward of what you’d do knitting flat.
Reading Your Knitting
For basic stitch patterns, an understanding of what the finished stitch pattern is supposed to look like and the ability to tell a knit stitch from a purl stitch make it easier to convert a stitch pattern from flat knitting to knitting in the round. Take seed stitch, for example. All you’re doing when you knit seed stitch is stacking knits on top of purls and purls on top of knits. Knowing that you can just look at your knitting and knit the opposite of the stitch you’re presented with and you’ll never have to pay attention to which round you’re on.
Other Considerations
What if you want to convert something a little more complex, like a lace pattern? The patterns that are easiest to convert are those that have a plain wrong side row (where you’re just purling or knitting across) because that way you don’t have to worry about trying to figure out how to work a lace pattern opposite and backward! Another important thing to keep in mind is that many stitch patterns knit flat have extra stitches (it’s that “plus 2” in a pattern that says to work it over, say, multiples of 6 plus 2). Those extra stitches balance a pattern out when it’s knit flat, but they aren’t necessary when working in the round, so take them out of your calculations and conversions. Likewise, any knitting instructions that come outside the main pattern repeat (before or after the section with the asterisk) should be omitted. These are the same balancing stitches that aren’t needed when working in the round.
Basic Conversions
Here are some of the most common stitch patterns you might want to convert into knitting in the round and how to do it:
Garter stitch: Knit and purl alternating roundsStockinette stitch: Knit every roundSeed stitch: Knit 1, purl 1 around on round one; purl 1, knit 1 around on round 2 (assuming an even number of stitches)Ribbing: Repeat the same round (knit 1, purl 1, knit 5, purl 2, etc.) on all roundsReverse stockinette: Purl every round