The gauge is the number of stitches and rows you need to create a specified width and length of fabric, and it affects absolutely everything you knit or crochet. Measuring your gauge before you start a project will ensure that your project comes out the right size—if you don’t, you’re throwing caution to the wind. Luckily, it’s easy! Here’s a little background on gauges, and how you can check your own.
A gauge is measured by the inch over a specific number of stitches and rows, such as 5 stitches per inch and 7 rows per inch. In other words, gauge is a measurement of how big or small each of your stitches are, based on several factors:
There are two measurements to consider: the width, called the stitch gauge, and the length, called the row gauge.
The bigger the variation between the gauge you’re actually working at and the gauge of the pattern, the more it affects the final size of the piece. For instance, if a pattern is 40 inches wide and the stitch gauge is 4 stitches per inch. The pattern would instruct you to work over 160 stitches. But if, because of the way you knit, your gauge is 4.25 stitches per inch, your piece would end up being only 37.65 inches wide instead of 40.
Almost all patterns specify gauge. It might be called something else such as “stitch measurement” or “tension,” but the information is the same. Sometimes patterns will give you the gauge over 4 inches, others over a fewer number of inches.
Suppose, for example, that a pattern shows the following:
Gauge: 20 stitches equal 4 inches (10 centimeters)
This means the pattern assumes that for every 20 stitches you complete, your fabric will be 4 inches wide. So:
20 (number of stitches) ÷ 4 (number of inches) = a gauge of 5 stitches per inch
Keep in mind: even if you buy the exact yarn, needle, or hook specified in the pattern, it doesn’t mean you will get the exact same result. These are the materials the designer used, but everyone knits and crochets a little differently. You still need to check your gauge by stitching a small sample.
If your swatch matches the pattern, great! You’re ready to start. If your swatch is too small, try again with a larger needle or hook; if it’s too big, try a smaller needle or hook. Continue moving up or down one size until your swatch matches the gauge indicated in the pattern.
In some cases, you’ll be able to get either the stitch gauge or the row gauge correct, but both won’t cooperate at the same time. In most cases it’s more important that you get the stitch gauge (width) right. Look through the rest of the pattern. Does it tell you to knit or crochet in inches rather than rows, like this: “Continue until piece measures 5 inches from beginning”? You would work the number of rows necessary to measure 5 inches; the number of rows is irrelevant. Generally, your row gauge will be close enough to that of the pattern if you’ve gotten the stitch gauge correct, and, in most cases, you should be fine.
Now that you understand how the gauge works, you can substitute another yarn. You just need to be sure the new yarn works up to the gauge in the pattern and that the resulting fabric is neither too stiff nor too loose (again, keeping in mind if this is the intent of the design).
Now that you’ve got your gauge, you can start on your project! By the way, your gauge swatches can also serve other purposes. After you work up a swatch, you can throw it in the washer and dryer to test for shrinkage and how well it holds up or if the color bleeds. You could also keep your swatches and use them for future reference; start a needlecraft diary of sorts. And you never know—you just might run a tad short of yarn and need to use the yarn from your swatch to finish your project. Have fun, and happy stitching!
From The Complete Idiot’s Guide to Knitting and Crocheting Illustrated, Third Edition, by Barbara Breiter and Gail Diven