What is Gauge?

Gauge is the measurement that allows any knitter to follow a pattern and get an end product the same size as the finished measurements in the pattern. Gauge measures the number of stitches within a certain width and the number of rows or rounds within a certain height on a finished piece. The pattern will state the yarn and needle size the designer used. These should be used as a starting point for matching gauge. We all knit and tension our yarn differently. Just because you use the exact same materials the designer used does not mean you will get a piece the exact same size. Differences in yarns, needle material, tension and knitting style -- even emotions -- can all affect the size of the stitches being knitted, therefore affecting the gauge.

For this reason, it is important to make a gauge swatch. If you are making a small piece, matching gauge might not be critical and you can skip this process. But if you’re making a garment or large project, gauge is important to match and therefore to make a gauge swatch. If your gauge is off, your piece could be a drastically different size than stated and you could run out of yarn. Designers use the gauge information to, as accurately as possible, determine the amount of yarn needed for a project, which they then list in the materials.

Making a gauge swatch will help you determine if you need to adjust your needle or your yarn to match the stated gauge measurements in the pattern. It is better to find out adjustments are needed after making a small piece of fabric than knitting a large piece and having to undo it. Your swatch should be made using the exact yarn and needle you plan on using for your project. Swatching with a different yarn as you wait for your project yarn to come in the mail doesn’t help you. The reason being that even though yarn weights say they are standardized there can still be a range of thickness in any given yarn weight. This difference can affect your gauge measurements.

How to Make a Gauge Swatch

Start with the needle recommended in the pattern and either the exact yarn in the pattern or a yarn that is the same weight and fiber content (or very close to the same fiber content). If your yarn is a different fiber than the one used in the pattern, it can behave differently and affect your ability to meet gauge. You want to create a swatch that is at least 6 inches square. The larger your swatch the more accurate it will be. You also want to work it in the same stitch pattern as the project or the stitch pattern stated in the gauge information in the pattern if one is provided. If your project is worked flat, work a flat swatch. If your project is worked in the round, you want to work your swatch in the round.

Flat Swatch

Cast on the number of stitches that should give you about a 6-inch width of fabric or larger and allow you to work in pattern. For example, if the gauge measurement reads 20 stitches x 32 rows = 4 inches in garter stitch, you want to work a swatch in garter stitch (knit every row) over at least 30 stitches (20 stitches/4 inches = 5 stitches per inch. 6-inch swatch x 5 stitches = 30 stitches). In this example, you’ll also want to work at least 48 rows (32 rows/4 inches = 8 rows per inch. 6inch swatch x 8 rows = 48 rows).

In-The-Round Swatch

As mentioned you want to work your gauge swatch in the stated pattern stitch. You also want to work it how you will be working the project. Tension tends to be tighter on a small circumference (i.e. a small number of stitches in a small area). If you are working a swatch for a sweater, which is larger in circumference, be sure to work a larger swatch. Measuring a round swatch is difficult. You can work your swatch in the round, cut it and then measure it flat. If working with wool yarn, you can work a steek in your swatch to make this easier. You can also work as follows:

With circular needles (or needles of choice for working in the round), cast on the number of stitches needed for your swatch. Work across those stitches. At the end of the row, do not turn your work. Slide your stitches back into position to work them from the start. Bring the yarn behind your work and leave a long float (length of yarn) that is a bit loose behind the work, then work across the stitches again. Repeat this process until you have the height needed for your swatch. Bind off. Now you can either cut the long floats in the back and then knot the ends close to the fabric to hold things in place while you block and measure, or if you leave the floats loose enough to lay the piece flat, you can block and measure as is.

After Working the Swatch

Next you want to block your swatch the same way you will block your finished piece. If you don’t plan on blocking (or ever washing) your finished project, you can skip this step. Blocking can change the measurements on a swatch dramatically (depending on the fiber and tension) so it’s important to follow the steps you would take with the finished project. You can measure your swatch before blocking so that you have a comparison of exactly what happened with blocking. For more on how to block, refer to that section of the Stitch Guide. Once done blocking, you want to measure a 4-inch square (because that is what gauge measurements reference) in the center of the swatch. You measure in the center because edge stitches have a tendency to be less uniform. The center stitches are the most stable and even. If your numbers match the gauge stated in the pattern, you are good to go.

If your numbers do not match, you need to work another swatch with a different size of needle. If you have fewer stitches over 4 inches than stated, you need to use a smaller needle so you can make more stitches in 4 inches. If you have more stitches than stated, you need to use a larger needle so you can make fewer stitches. You won’t know exactly whether to change by one needle size or more than one. You just have to give it a try. If your numbers are way off, then you probably need a needle more than one size different. Continue making swatches until you find the best match for gauge with your needle and yarn. If it’s a real struggle, you might try a different needle material, like switching from aluminum to wood or vice versa. Yarn flows over the needle material differently and it can affect gauge a bit. If that still doesn’t help, you may have to try a different yarn. As mentioned, even though yarn is labeled with standard weights, there is still a variance in thickness within each size category of yarn.

When Exact Gauge Matters

Being off on gauge by even a little bit can greatly affect the overall finished size of your piece in a large project and the amount of yarn used. Again, on a small piece, it’s not critical. Let’s look at some numbers and compare so you understand. Using the same gauge example from the flat swatch instructions (20 stitches x 32 rows = 4 inches in garter stitch), let’s say your swatch ended up being 19 stitches x 30 rows in a 4-inch area. You decide that’s close enough and make the whole pattern for an afghan exactly as it reads. You cast on 200 stitches intending to make a 40-inch-wide finished afghan. Your stitch gauge was 19 stitches = 4 inches. That’s 4.75 stitches per inch, which means your finished afghan will be about 42 inches wide (200/4.75 stitches = 42.11). So your afghan is 2 inches wider than stated. Now let’s say the pattern says to work in garter stitch until your afghan is 50 inches long, or about 400 rows. Your row gauge is 30 rows = 4 inches or 7.5 rows per inch. Your finished afghan worked to 50 inches has 375 rows instead of 400 (50 x 7.5 rows). So you worked fewer rows but have a wider afghan. You only bought the exact amount of yarn the pattern stated. Do you have enough yarn? That becomes the question. You may be playing yarn chicken (this is what it is called when you aren’t sure if you are going to have enough yarn to complete a project) to get to the 50 inches mark or you could end up being fine. Most designers usually include more yarn than is strictly needed in the materials as a precaution, but do you want to risk it? That is up to you.

Just to be thorough, let’s see what happens if you use the same numbers in the pattern but you are making a garment. As above, you cast on 200 stitches and should have a finished bust circumference of 40 inches on your sweater. Your bust measurement is 38 inches in circumference, so you should have 2 inches of positive ease. That’s not a lot, but maybe you wanted something with a little more fitted look. Now let’s say the gauge from your swatch is 21 stitches x 32 rows = 4 inches. That means you are making 5.25 stitches per inch. You say close enough and make the garment. With this gauge, your finished bust measurement is 38 inches (200/5.25=38). You put your sweater on and it hugs the body tightly because now there is no positive ease. All that work and you don’t have the fit you thought you were going to have. If row gauge is off too, it can affect things like how tight the underarm is or how deep the neckline is. A small number can have dramatic results. Take the time to swatch and save yourself some aggravation.

As you work your piece, stop and check your measurements often. Your tension can change as you become more comfortable working on the project. If it does, you will want to catch it and make adjustments as early as possible. You can stop at any point, use scrap yarn to hold your working stitches and block it to check. It takes some time, but again, it will save you from having to redo a larger chunk of work. You want your piece to fit or be correct when you are done.

What to Do With Your Swatches

If you make gauge swatches often, you end up with a lot of small pieces of knit fabric in varying yarns, colors and sizes. You can start a swatch library. Label each swatch with the yarn information (you can attach a yarn label), the needle you used (size and material) and the gauge measurements. Then you can keep them all as a reference for the future. Maybe you’ll use that same yarn on a future project in the same stitch pattern. You can check that old swatch for gauge and move right along. Sometimes it’s also nice to have a little reminder of the work you have done. There are other fun things you can do as well: Use your swatches as coasters. Bundle up similar ones and gift them as coasters or as washcloths (if they happen to be cotton). Hang them on the wall. Sew them together into a bag or blanket.