Essential Guide to Knitting Gauge

So what exactly is gauge? Gauge is the number of stitches you have within specific measurements of a knitted fabric. We all knit differently, so tension can vary a lot from one knitter to another. This means two knitters could use the exact same needles and yarn, but within a 4 inch square area of knitted fabric, one person could have 20 stitches and 20 rows and another could have 30 stitches and 30 rows.

Knitting patterns will state the designer's gauge, which you will need to match in order to get a finished project which is the correct measurements. If you don't have the correct gauge, you can end up with a finished project which is much larger or much smaller than the finished measurements given in the pattern. This also means you may risk running out of yarn, as if your project is much larger than it should be you'll end up using a lot more yarn. Correct gauge is particularly important for clothing, because if your gauge is incorrect you can spend a lot of time knitting a project that ends up being completely the wrong size.

How Do You Get the Correct Gauge for a Project?

To check your gauge you need to knit a gauge swatch. A gauge swatch is a small sample of knitted fabric, it will need to be knitted in the same stitch pattern and use the same needles and yarn as you're planning to use for your project. You will then measure your swatch and if it doesn't match the project gauge you'll need to change the size of needles you're using and knit another swatch, repeating this process until you know which needles you need to use to get the correct gauge.

Knitting patterns should give you the gauge required for a project and tell you what stitch pattern to use for your gauge swatch. See an example below:

15 sts & 25 rows in a 4 x 4 inch (10 x 10 cm) square worked flat in stockinette stitch, blocked.

For the above example you'll need to knit a square of stockinette fabric. It will need to be large enough to be able to measure a 4 inch square within it, so you'll likely need to knit at least a 5 inch square. A larger swatch will give a more accurate gauge measurement as it gives you more time to get used to the stitch pattern, so will more accurately show the tension you're likely to have for the majority of your final project. This is why many knitters will choose to knit a 6 inch square or larger.

Stockinette stitch is a stitch pattern which tends to curl, so it's a good idea to include a few of rows of garter stitch at the start and end of your swatch and knit the first and last few stitches of each row in garter stitch. This helps the project to sit flat and makes it much easier to measure - make sure you don't include any of the garter stitch when measuring your swatch.

For the above example the instructions also state that the swatch needs to be worked flat. You'll need to knit your gauge swatch using the same method as will be used for your project, so if your project is knit in the round your swatch will also need to be knit in the round.

If a pattern uses multiple needle sizes the gauge instructions will usually also tell you which needle size to use; in this example no needle size is listed so you'd just use the needle size listed within the pattern details. You need to ensure you use the same needles you plan to use for your project, as using different needles can result in a different gauge. For example metal needles tend to result in a looser gauge than wooden needles, but even different sets of needles made from the same material can give totally different results.

If your project is knit in the round using circular needles you'll need to use the same cable length as you'll be using for your project, as this can have a big impact on your gauge. Most knitters will get a tighter tension when knitting a small circumference project with 9 inch circular needles than they would when knitting a larger circumference project with 24 inch circular needles. This also means for projects like sweaters where you knit the body and the sleeves in the round, you may wish to knit two gauge swatches with the different circular needle lengths required, as you may need to use a different needle size for the sleeves to get the same gauge as the body.

It's important that you block your swatch before measuring it - unless the pattern states otherwise. When you block a project the size can change depending on the yarn used, which is why it's important to block your swatch to get the accurate gauge your finished project will be. You should block your swatch and generally treat it exactly how you plan to treat the finished project, so if you're planning to wet block your finished project you should use the same method for your swatch.

Once your swatch is finished and blocked, it's time to check if you've got the correct gauge. Measure 4 inches (10cm) horizontally across the middle of your swatch and count the number stitches along this line. Then measure 4 inches (10cm) vertically up the middle of your swatch and count the number of rows along this line. See if these numbers match the pattern gauge, which in the above example was 15 stitches and 25 rows. If you don't have the correct gauge you'll need to change your needle size and try again. You'll need to go up a needle size if you have too many stitches and go down a needle size if you don't have enough stitches. Stitch gauge is usually more important than row gauge, as a lot of patterns will just ask you to knit to a certain length rather than for a specific number of rows. This means that if you have the correct stitch gauge and your row gauge is close but not exactly correct you're probably ready to move on from swatching and start your project. There are some exceptions to this, the orientation at which you knit some projects may make the row gauge more important, this is less common so if this is the case it may be stated in the pattern.

Another important factor to bear in mind when swatching is you need to see if you're happy with how the fabric looks. If you have the correct gauge but you don't like how it looks it may be a good idea to switch to another yarn and try another swatch until you're happy, so you don't find yourself with a finished project you don't like the appearance of.

How Do You Knit a Swatch in the Round?

When you need to knit a gauge swatch in the round you don't have to knit an entire tube. You can just knit a small square as you would when knitting flat, except you don't turn your work when you reach the end of your row. This means after knitting your first row, simply slide your knitting back to the other end of your circular needle. Your working yarn will be at the wrong side so just carry this loosely along the back of your work and start knitting again. Repeat this for every round so you never turn your work.

When you knit a swatch in the round the edge stitches will usually end up quite loose, but you don't need to worry about this as your swatch should be large enough that you can measure gauge in the centre where these loose stitches won't be included. The back of your swatch will also be quite messy with all the strands carried across from the start of each round. You can choose to cut these strands to make your swatch neater, but you won't then be able to re-use the yarn from your swatch if you need it for your project.

Do I Need to Swatch?

Whether you swatch for a project is your choice, lots of knitters don't enjoy knitting swatches so will avoid this step when possible. It is however important to remember that knitting a gauge swatch is the only way to ensure your project ends up being the correct size. If the size of your finished project isn't important to you, for example if you're knitting a shawl and you don't mind if it's larger or smaller than the specified measurements, you may choose to skip knitting a swatch. There is still a risk of running out of yarn if you don't have the correct gauge, so it can be a good idea to have some extra yarn if you're skipping the swatching process.

With some projects you can just use the beginning of your project as your swatch. Some knitters just measure the gauge of their project after they've made some progress and see if they've got the correct gauge. You could also transfer your stitches to waste yarn and block your project at this stage to get a more accurate gauge measurement. On projects where perfect gauge isn't essential to you, you may choose to just measure the gauge of your unblocked project and take an educated guess based on previous experience blocking projects which used similar yarn, as to whether the blocked gauge is likely going to be close to the required gauge.

Another option for knitters who want to avoid swatching can be just knitting a small swatch. This won't be as accurate as knitting a larger swatch, but for knitters that don't enjoy swatching this can still give a rough idea of gauge without needing to spend much time on it. It's not very accurate, but it's better than not swatching at all. I know I've certainly done this for projects where I wasn't too bothered if the finished size was perfect.

If you've knitted patterns from a designer before and have managed to get gauge without changing from the recommended needle size, this doesn't mean you don't have to swatch for their other patterns. Lots of things can change your tension, including your mood, lots of people's tension also naturally changes over time. If you're not using the same yarn as the designer this can also cause a different resulting gauge. This is why it's important to swatch for every project, rather than trying to base this on a previous project. You can however use knowledge of patterns you've knitted by a designer before to decide what needle size to try for your first swatch. If you know you've previously had to go up two needle sizes when knitting a pattern by the same designer, it may be best to go up two needle sizes for your swatch.

Do You Need to Purchase Additional Yarn for Gauge Swatches?

Patterns won't usually include the amount of yarn needed for swatches within the required yarn amounts, however most designers will add around a 10% margin of error to the required yarn amounts to ensure you'll have enough yarn for your project. This will usually be enough for your swatch. It is however important to remember that in most cases you'll be able to unravel your swatch even after you've blocked it, to then re-use that yarn in your project if you find yourself running low on yarn.

How Do Designers Use Gauge?

When designing patterns designers work out their gauge to then use this for calculations within their pattern. This is particularly useful when designing patterns in multiple sizes. For example, if you know an inch of width requires 5 stitches, you then can calculate exactly how many stitches you'll need to reach a certain measurement. This is why gauge is so important, because usually all the maths used within a pattern is based around the gauge.