One of the fundamentals of knitting that it’s taken me the longest to truly absorb and incorporate into my process is that if you really want something to fit correctly in the end, as you’re knitting toward whatever length your project or pattern calls for (e.g. “knit until piece measures 7″ from cast-on edge”) you must count rows rather than measuring lengths. (Advice offered here by Kate Gagnon Osborn three years ago in a larger post about fit.) There are a couple of reasons why:
1) Measuring knitted fabric is an iffy proposition to begin with. A grippy or curved surface, the pressure of your hand, even wishful thinking can all influence it.
2) The fabric might change once it’s been soaked or washed in whatever way — it could grow, shrink, widen, shorten, you name it. If you’re just measuring your raw knitting and not taking into account how it will change in the end, that measurement could backfire on you.
Length is determined by number of rows and how tall each row is (i.e., your row gauge) and only a blocked swatch can tell you that. If your swatch doesn’t change — the row gauge is identical before and after you soak it — then only #1 up there applies. In that case, if you want to knit to the intended length and determine that with a measuring tape, ok.
But if your swatch does change, it’s a different story.
The way to be truly accurate, no matter what, is to calculate how many rows — at your row gauge — are needed to equal the intended length, and knit that many rows. Even if your swatch doesn’t change and you’re knitting two of something (sweater fronts, sleeves, sock cuffs …) counting rows is the way to make sure they match. To make keeping track simpler, try putting a pin in your work at helpful intervals, use the features of the fabric as a guide, or employ this elegant little trick.
The two half-sleeves of my fisherman-in-progress above are identical, except the top one has been soaked and laid out to dry (with no pinning or stretching or manipulation of any kind, so I could find its natural gauge — this is my sleeve swatch), whereas the bottom one is virgin knitting. As you can see, this fabric (heavily textured Arranmore) pulls up a bit when soaked. Therefore, if I were to knit each sleeve to 18″ as told by a measuring tape, and then block my finished pieces, they would turn out too short. I think I’ve counseled before to think of pre- and post-block gauge in percentage terms, or just “keep it in mind,” but the precise answer is counting rows. My row gauge here is 7.3 rows per inch — measured on this blocked fabric over 9″ to be really certain. So if I want my sleeves to be 18″ long from edge to underarm, I need to knit 131 rows from cast-on (which will be longer than 18″ in virgin form but will shrink to that length when blocked). In this case, there’s a cable cross every sixth row, which makes it easy to add them up, and I’ll also make sure both sleeves finish on the same row of the chart to guarantee they’re exact twins.
See also: How to knit and measure a gauge swatch
PREVIOUSLY in Hot Tips: Test your pick-up ratio