Gauge Is Not a Four-Letter Word

Like any creative endeavor, knitting is rife with the potential for individual choices. Colors, yarns and styles abound. We can follow a pattern exactly, alter bits and pieces according to our personal preference, or design our own garments. But there is one thing that none of us can challenge: Gauge determines size.

Many of us have spent hours and hours knitting a sweater only to be disappointed by the fit, which is usually because we did not get the specified gauge dictated by the project instructions. If we had knitted a gauge swatch -- and washed and blocked it, we could have determined whether our combination of yarn and needles would yield the proper result. And if the gauge was wrong, we could have changed needle size, yarn or both.

These three swatches were knitted with the same number of stitches and rows using size 5, 6 and 7 needles.

What Is Gauge?

In the knitting world, the gauge of knitted fabric is how many stitches, and sometimes how many rows, there are in a particular area. Most commonly, gauge is expressed as the number of stitches per four square inches of knitting, but sometimes it's expressed as a per-inch number. Both yarn weight and needle size affect the gauge. Most yarn labels include the manufacturer's recommended gauge, which is what they suggest to create the best fabric. The recommended gauge is based on stockinette stitch. Let's look at how needle size affects gauge.

For this example we're using a cotton yarn with the recommended gauge of 5 stitches per inch on U.S. size 6 (4mm) needles. We knitted three swatches, all with 25 stitches. Of the 25 stitches, four are edge stitches that won't count toward the gauge, and the other 21 are knit in stockinette stitch. The first swatch is knit with the recommended size 6 needles, and the result is exactly 5 stitches per inch, which was measured over 2 inches.

A swatch knitted on the recommended needle size, in this case size 6, yields the recommended gauge: 5 stitches per widow.

To illustrate how things change with gauge, the next swatch was knitted with the same stitch count on U.S. size 5 (3.75mm) needles. The result was 11 stitches in 2 inches or 5.5 stitches per inch.

Using one needle size smaller, size 5, produced a swatch with 5.5 stitches per inch.

To show the change in the other direction, a third swatch was knitted on size U.S. size 7 (4.5mm) needles, and the result was 9 stitches in 2 inches or 4.5 stitches per inch.

Using one needle size larger, size 7, produced a swatch with 4.5 stitches per inch.

Not all of us knit to the recommended gauge. It's possible you could knit the same swatch on size 6 needles and get a result that matches what we got on either size 5 or 7 needles. If you knit your swatch and have too many stitches per inch, the knitting is too tight, and you should knit it again on a larger needle. If you have too few stitches per inch, the knitting is too loose, and you should try again on a smaller needle.

Why Does Gauge Matter?

So why does all of this matter, especially when we're talking about the small difference of one-half of a stitch per inch? If you're knitting a baby blanket, a scarf or an item that doesn't have to fit, gauge matters less. If you're happy with the gauge swatch you get, of course, you can knit at a gauge that differs from the instructions. However, if you're knitting a sweater, a half-stitch-per-inch difference can start to add up.

Let's say your sweater pattern calls for a gauge of 5 stitches per inch, and you're knitting for a 40-inch finished chest circumference. For the front and back, you'll work with 100 stitches each: 5 stitches x 20 inches = 100. However, if you did not check your gauge and are actually knitting with 5.5 stitches per inch, your resulting back and front pieces will measure only 18 inches each, and your sweater will have a finished chest circumference of 36 inches, a full 4 inches smaller than you expected. On the other hand, if your gauge is a looser 4.5 stitches per inch, you'll get a sweater that measures about 44 inches, which may be far too large. All this is to say it's worth the effort to do a gauge swatch before you put all those knitting hours into making something that doesn't fit.

Using Gauge to Your Advantage

Now that you know why gauge is so important, you can turn things around and intentionally use a different gauge to get a size that may not be offered. In this issue we've included a free pattern for Tangerine Smoothie designed by Sara Louise Harper. The pattern gauge is 19 stitches in 4 inches or 4.75 stitches per inch. Finished chest measurements are 38 (40, 44, 48) inches.

What if you know your preferred finished chest measurement is 38 inches, an option that isn't offered with this design? A little math tells us that if we knit this sweater at 4.5 stitches per inch instead of 4.75, the finished measurement will be 38 inches. In fact, using a gauge of 4.5 stitches per inch, you can follow the instructions for size small, medium, large or extra-large, and instead get a sweater with chest measurements of 38, 42, 46 or 50 inches. Pretty cool, huh? Of course, the trick now is to achieve that gauge. This new gauge may not be possible if you use the same yarn that was specified in the instructions, but if you choose something that's ever-so-slightly heavier, you're in business.