All About Gauge | Purl Soho

If you’ve ever knitted a garment, hat, mittens, or socks, chances are you’ve had issues with size and fit. After a big investment of time, money, and emotion, few things are more disheartening than coming to the end and finding your finished knit doesn’t look or feel the way you hoped and expected. Happily, you can avoid this too-common problem by taking time at the beginning to focus on gauge. It’s tempting to skip this step in your eagerness to cast on, but the extra effort now will prevent delays and disappointment later.

What Is Gauge?

For the purposes of this discussion, “gauge” (or “tension” in some parts of the world) means the number of stitches and rows per given measurement. Gauge is almost always given per inch or per 4 inches (or 10 centimeters).

You may think that just following a pattern’s yarn and needle recommendation will suffice, but please believe us that everyone knits on a spectrum somewhere between very loose and very tight, including the person who wrote the pattern! This means you need to find the right needle size and yarn for you and your project. The answer lies in the critical step of knitting a gauge swatch (we explain how to make one below).

Note that even if, through swatching, you find the right needle/ yarn combo to get the proper number of stitches per inch, you also need to consider the fabric you’re creating. You may find that, at the right gauge, the swatch feels too loose or tight, that it stretches too much or is too fuzzy to show the stitch pattern. You might decide the yarn isn’t a good match for the design after all. On the other hand, you might find you love the fabric and can cast on with confidence!

What Affects Gauge?

Several factors will influence the size and qualities of your gauge swatch…

Tension

This refers to how tightly or loosely you hold and manipulate the working yarn, which affects the size of your stitches. No two knitters are alike in this, and your own tension can change with intangibles like mood or fatigue. That’s why it’s important to create your gauge swatch under conditions and with tools as similar as possible to those you’ll use when knitting the actual garment.

Yarn

Most yarn labels give either a single recommended gauge (number of stitches per inch or per 4 inches/10 centimeters) or a range. If substituting yarn, try to choose one whose recommended gauge matches that of your pattern. Also look at fiber content. If the pattern was designed for a fuzzy yarn such as mohair, it’ll be easier to achieve the right gauge and fabric with another mohair yarn than with a smooth fiber that lacks halo, like silk or cotton.

Needles

Larger needles mean larger stitches and fewer per inch; smaller needles will give you more stitches per inch. If you know you knit with pretty standard tension, or you aren’t sure, start by using the needle size given in the pattern. If substituting yarn, check the label to see what size needle is recommended to get your intended gauge with that yarn, and perhaps try that first. If you’ve found in the past that you often need to go up or down a needle size because you’re a tight or loose knitter, keep this in mind and start with needles one size larger or smaller than called for.

These swatches are knit in Purl Soho’s Understory using four different needle sizes: (Clockwise from top left) US 3, US 5, US 7, US 9.

All About Gauge | Purl Soho

Size isn’t the only factor when it comes to needles; gauge can vary with material (wood, metal, plastic, etc.) and with the use of circular or straight needles, too. For the most accurate results, use the exact needles you intend to use for your project. You can even mimic circular knitting in a swatch without having to knit all the way around: see our tutorial here.

Stitch Pattern

Gauge is most commonly given for stockinette stitch, but many designers also provide gauge for the stitch patterns used in the piece. You may balk at the thought of working a cabled or colorwork swatch, but don’t, especially if it’s the primary stitch pattern in your project. A swatch can provide essential info. For example, even if your stockinette gauge is correct, the concentration required by other stitch patterns might cause you to knit with greater tension, resulting in a too-small garment. Start with the stockinette gauge to make sure your yarn will work for the project, but don’t skip the other stitch patterns.

All About Gauge | Purl Soho

How To Create A Gauge Swatch

  • Your swatch should be larger than 4 inches square, so you can comfortably measure that area without including edge stitches. Even if the gauge is given over 1 inch, a 4-inch measurement will give you a more trustworthy gauge, avoiding partial stitches and the effect of slight variations in your knitting. To determine the number of stitches to cast on, take the number you expect over 4 inches and add about an inch’s worth. For stitch patterns that repeat, adjust the stitch count so you can work one or more full repeats within your edge stitches.
  • Cast on using a method that’s relatively loose and stretchy. A tight cast-on or bind-off can give you a misleadingly tight gauge on the rows closest to that edge, and it won’t be flexible when you block your swatch. We like to use a basic Long Tail Cast On
  • Knit until your swatch measures a little longer than 4 inches. If your stitch pattern repeats vertically, finish at least one full repeat before binding off.
  • Bind off loosely and cut the yarn.
  • Measure the gauge before blocking or washing your swatch. This will give you a set of numbers to compare with your piece as you knit it, pre-blocking. Lie the fabric flat, pinning the edges, if necessary, to prevent curling (but without stretching the fabric).
  • Use a ruler or measuring tape, count the number of stitches in four inches across, holding your ruler along the bottom of a row. It might help to count if you imagine each stitch as a “V” and use a pencil or a needle tip to point to them as you go. Measure in a few different places and take the average if the numbers vary. Be sure to count a quarter, half, or three-quarter stitch if the four inch mark doesn’t fall at the exact end of a stitch! (NOTE: The stitch gauge in the example below is 18.75 stitches over four inches.)
All About Gauge | Purl Soho
  • Do the same thing vertically, counting rows. (NOTE: The row gauge in the example below is 27 stitches over four inches.)
All About Gauge | Purl Soho
  • Wash and/or block your swatch as you expect to with your finished piece. Too often knitters skip this important step, with unhappy consequences! Certain fibers are likely to grow after washing, like cotton, linen, or silk. Even if you’re using a more elastic fiber like wool, the fabric might grow or shrink, and if your gauge changes even a little, it can mean a big difference in the size of the finished piece. Also, if you’re making a sweater, don’t forget that it will be hanging on your body, not just lying flat, so if the fabric is thick or made from a fiber that tends to grow, consider hanging your swatch to dry to show the effect of gravity.
  • Repeat the measurements with the finished, blocked swatch. This is the gauge that should match the one given in your pattern. Also take note of the effects of blocking on the fabric: Is it softer? Are the stitches more open, or has the yarn “bloomed” and become thicker and loftier? Are you still happy with the result?
  •  Too many stitches per inch? Make another swatch with bigger needles. Too few stitches per inch? Try smaller needles!

What to do if the stitch gauge in your swatch is accurate but the row gauge isn’t? In most cases you should use the needle that gives you the proper stitch gauge. You can probably more easily adjust the length of your piece to compensate for the difference in rows, either by working more or fewer rows than the pattern specifies or when blocking. However, if the garment is fitted and/or involves complex shaping, consider trying a yarn with different properties that gives you correct stitch and row gauges.

Swatches for Other Stitch Patterns

Ribbing

Measuring gauge in ribbed fabric can be a head-scratcher: Isn’t the whole point of ribbing that it can be stretched to a variety of widths? Sometimes the pattern will use wording like “slightly stretched,” but even that is open to interpretation. One good approach is to take a measurement with the ribbing completely relaxed (unstretched), then stretch it to its widest and take another measurement, and use the average of the two.

The stitch gauge in this example is 15 stitches over four inches (remember the purl stitches of the rib pattern are hiding!).

All About Gauge | Purl Soho

Garter Stitch

Garter stitch also presents its own set of issues. To count garter stitches, instead of “V”s, count the purl bumps or little “frowns” over a four-inch span. For row counts, patterns in garter stitch may specify gauge in “rows” or in “ridges,” which are the pronounced horizontal stripes that span the width of your swatch. The important thing to remember is that two garter rows make up every garter ridge. Skipping the cast on row, count every ridge on the right side of the swatch; if the pattern specifies rows, simply multiply by two to get your row count.

The row gauge in this example is 25 rows (or 12.5 ridges) over four inches.

All About Gauge | Purl Soho

Picked-Up Borders

You may want to knit a swatch for picked-up borders like button bands and collars that are in a different stitch pattern than the rest of the piece, even if the pattern doesn’t specify this gauge. The swatch will help you determine how many stitches to pick up along a given edge, which might vary from the number in the pattern if you knit your border at a different gauge.

Using Your Gauge Swatch

Once your swatch is finished, put it in your project bag and hang onto it! You might want it later on to compare with your work-in-progress, or to use as a sample when shopping for buttons, contrast-color yarn, or other embellishments.

Once you’ve cast on your actual project and knitted several inches, take gauge measurements as best you can and make sure they’re not significantly different from your unblocked swatch. Once we get into the rhythm of knitting a larger piece, we sometimes relax and so does our gauge. (Or we become anxious and knit more tightly!) If you find your garment’s gauge is different enough that it might cause size issues, consider starting over with a different needle size, or blocking your work-in-progress to see whether it matches the blocked gauge swatch.

Look at your gauge swatch as an essential piece of information, like everything else in your pattern. The knowledge that you’re knitting at the right gauge will help you experience both the process and the finished product with less stress and more joy!

All About Gauge | Purl Soho