Knitting gauge swatches – How & Why

A step-by-step tutorial on how to knit swatches and get gauge every time. Plus many common mistakes you need to avoid.

Knitting is a handcraft. As such, we all knit with different techniques, a different tension, a different needle material, a different needle brand, and/or a different yarn. The result: no two knitted fabrics are the same. So, to make patterns (or charts) work, you need to knit a swatch and this tutorial is all about the fine details to get gauge.

Per definition, a swatch is a simple rectangular piece of knitted fabric of a sufficient size that you can use to compare the fabric you create with that of someone else via a tape or a ruler. By adjusting factors like the needle size or the yarn, you can manipulate your knitting in a way that both swatches are identical. This process is known as getting gauge in knitting. This process will also show how needles, yarn, and a stitch pattern interact.

The theory: When you meet the gauge of a fellow knitter or the designer of a pattern, this means you can follow their instructions word for word and the result will be the exact same size.

The process of knitting a gauge swatch is incredibly easy – even if you just started learning how to knit. What’s a bit more difficult, even for many advanced knitters, is meeting the specifications of the pattern. So, I’ll show you how to knit a gauge swatch first, then how to get gauge, and further down below important tips and tricks!

Note: I earn a small commission for purchases made through links in this article.

How to get gauge

Now, you might notice that you knitted your swatch diligently, measured things out, and your readings and the numbers provided in the pattern don’t match. You are off. So what can you do? How do you actually get gauge?

First, there are 4 tips to adjust your gauge, and further down below you will find 5 common mistakes you need to avoid. So make sure to read all the way to the end.

#1 Change needle size

The obvious and easiest choice is picking a different needle size. If your swatch ended up being too big, just go down one (or possibly even two) needle sizes, knit another swatch, block it, and see where it gets you. This might seem tedious but I promise you it’s less effort than knitting a full sweater in the wrong size.

I recommend using eyelets (so k2tog followed by a yo) or purl stitches in the first row to mark the needle size you used. E.g. 3 eyelets and 3 purl stitches could indicate a 3.75 mm needle.

One thing you might delve into is picking needles from a different brand. I personally noticed how most needles differ a tiny bit. So, typically, a needle marketed as 2 mm (size 0) is often 1.95mm or 2.1 mm thick. And this can make a significant difference. Because that 0.1mm would be a difference of 5%. So, for every 25 rows, you would end up with one additional row (the stitches are 5% bigger; 5% x 25 = 100%).

Important: And that is one of the reasons why I don’t recommend changing needle material & brands mid-project. Or rather, you should know that this can have a big influence on your gauge.

#2 Change needle materials

Another thing that greatly influences your gauge is the needle materials. Bamboo has quite the high friction whereas coated steel is super slick. And as a result, you might end up knitting a bit tighter or looser (check out my review of the best interchangeable knitting needles in case you need some input).

Since it is very difficult to predict what will happen in your case, and you probably prefer one material over another on top of that, this is of course more a means of last resort. But if you can’t make things work by changing needle size, it’s certainly a viable option.

#3 Change yarn

You also have to realize that the yarn itself takes space on a knitting needle. The same amount of stitches will need the exact same space on the needles if you bunch them together – no matter your needle size (that effect can be used to create neater ribbings).

And here’s the problem: Not all Fingering or DK weight yarn has the same diameter. They are roughly similar but there’s no standard saying: A worsted yarn always has this diameter, is spun in that exact manner, and has exactly that many wraps per inch (wpi).

Sometimes a pattern and a yarn just won’t go together. And then you can either change to different quality or give the pattern a pass.

#4 Tension your yarn differently

A typical knitting gauge has a number of rows and stitches, and, apart from the yarn and the knitting needle, those are mainly determined by your tension. Now, I will say that it is very difficult (if not impossible) to change your tension on a whim, but I still want two show you a couple of hints.

A) Row Gauge

The row gauge is the number of rows you need to cover a certain length of fabric. Now, theoretically speaking the size (read height) of your stitches is determined by the barrel of your knitting needle. The bigger the needle, the bigger the resulting loop will be – and once stretch things out, this will create your row gauge.

But not all knitters tighten up before they drop each stitch off their needles. Some may knit a bit looser. As a result, the loops will be bigger and thus your row gauge. And that’s certainly something you can toy around with.

B) Stitch gauge

The stitch gauge is the number of stitches you need to cover a certain length of fabric in the same row. This is mainly influenced by the strand between two stitches. So, if you look at a row of knit stitches under magnification, you can see how all stitches are connected via a little bar.

The length of that strand is governed by two factors. First, there’s the knitting needle itself. The bigger the needle, the longer the strand has to travel when you, for example, transition from a knit to a purl stitch.

But there’s another factor: The way you bunch or stretch out the stitches on the right needle is also an important factor. The closer the previous stitch sits on the right knitting needle, and the more you tighten up before you drop the current stitch off the left needle, the shorter that strand will be. Likewise, you can also stretch your stitches out on the right needle to create a looser row gauge (fair isle knitters might know this trick).

C) Tensioning methods

And last, but certainly not least, you could try to adjust your tensioning method. For example, I typically keep the yarn wrapped around my pinky finger twice and let it rest loosely on top of my index finger. But if I only wrap it around the pinky finger once, my tension will be a bit looser and as a result my stitches.

I could also wrap the yarn around my index finger to tension the yarn. And again, this will have an influence on my gauge. Not because either method was looser or tighter in and by itself but because my hands and body will handle it slightly differently.

Now, as I said, I personally believe that adjusting your tension on a whim is just not feasible. Maybe for a couple of stitches, sure. But by and large, advanced knitting happens subconsciously and it would take incredible willpower and concentration to knit with a looser tension for this project, and a tight tension for the next.

Tips for knitting an accurate gauge swatch

In the next paragraph, I want to highlight a couple of essential tips and tricks you need to observe when knitting a gauge swatch. Because depending on your project, simply knitting a square piece of stocking stitch won’t be enough. Here’s what you need to consider.

#1 Check your rulers and tapes

If you take a look around Etsy, you will quickly find these special little gauge swatch rulers. A lot of them will also have a needle size gauge worked into the frame. So, all in all quite lovely. And of course, there are many cute tape measures as well.

Now, I don’t want you to panic and I also want to be clear that a lot of small business owners and crafters create exception quality. But still, I urge you to check if the markings are off. This happened to me quite a lot and 2 millimeters could mean one full stitch. It takes only a second if you have a good ruler at home – these are typically standardized.

#2 Knit swatches that are big enough

There are two reasons why you need to knit big enough swatches. And big enough means more than 2×2 inches. Why?

First of all, knitting behaves differently around the edges. I have a tutorial on knitting neat edges where I show you why your edges may end up with a different tension. So, you absolutely need to sure that there’s a margin of 4-5 stitches to either side to get accurate readings.

The second problem: A typical gauge doesn’t list fractional stitches (something I wish would change). So, let’s imagine you knit a 2×2 inch swatch with chunky yarn, and there are only 4 stitches that fit into that square. But there’s a half stitch as well. Should you count it or not? (by the way, here’s how to count stitches in knitting). Did the designer ignore it or not?

The bigger your swatch, the less those fractional stitches will matter. In the example above, counting or not counting a half stitch would mean a difference of 11 percent. But if the swatch is twice as big, the error would only be half as big (i.e. 5.5 percent).

#3 Swatch in the round when the pattern is in the round

If you want to knit a project in the round, you absolutely need to make sure that you also knit a swatch that will reflect your intended knitting technique. Otherwise, your readings might be off as well.

Why? Well, most people knit and purl with a slightly different tension. When you knit stockinette stitch in the round, you will never need to purl. But if you knit it flat, you have to alternate between knit and purl rows. And if your purl tension is a bit looser (very common among English knitters), the result will be a different row gauge.

There are two ways to do approach this.

A) knit in the round and cut open

For example, you can easily cast on the same number of stitches in the round (either using magic loop or double-pointed needles) and then cut things open so you can measure it.

The problem: 40 stitches in the round won’t give you a big tube and you will end up shuffling your stitches around and possible ladders (or smaller tension imbalances around the gaps) will also influence the fabric quite a lot.

That being said, if your pattern calls for steeking (e.g. a Fair Isle Cardigan or so), then you can use the swatch to practice steeking and see how secure things are with the yarn you are using. Typically, you don’t have to do this. Just make sure that you don’t get too close to the edges when you measure.

B) knit flat – but only from the front

Instead, you can also knit your swatch flat. But when you come to the end of a right side row, you don’t turn your work around. Instead, you slide it back to the right end of your needles (so this only works with circular needles or dpns), drag the working yarn all the way around, leave a bit of slack, and start knitting. If your tension is excellent, you can also try to knit backward instead.

This will simulate your knit in the round tension quite efficiently but will be faster to knit and easier to measure.

The problem: Your swatch needs to be quite a bit bigger as the fabric will behave even weirder around the edges. You can try to fix this a bit by knitting the first and last stitch through the back loop. Also, it’s only an approximation of your knit in the round tension. Your knitting rhythm will be a different one and thus possibly your gauge.

#4 Wash, block & weight your wash

A lot of yarn will behave quite differently after the first wash. This could be because there are still residues of spinning oil (typical for cashmere yarns) but a whole lot of other reasons as well. But sooner or later, and typically sooner as you will probably block it, you will end up washing your finished project.

So, it’s vital that you treat your swatch the same way you would treat your finished work. If you plan to put it in the washing machine (make sure it’s a superwash yarn), then throw your swatch into the washing machine as well. That’s the only way to avoid unpleasant surprises later on.

And the second thing you need to consider: yarn can be quite heavy. There’s probably 200 grams of yarn – and sometimes even more – weighting down on the shoulder seams of a sweater. And this will stretch out your fabric. Your heel hammering against the heel flap of your socks when walking is a similar issue.

To avoid equally unpleasant surprises, you should consider weighting your swatch. So, after you blocked it and it’s completely dry (important, as the water would add weight), take a couple of books (or any other heavy object) to secure the swatch at the edge of your table. And then, use some small weights to simulate the stress. Stitch markers can be a great choice.

Don’t take something that is too heavy. Just a gentle touch (except your yarn is super bulky and heavy). Let it hang out overnight and then take another gauge reading and if and how much the numbers differ. For example, a lot of alpaca yarn is notorious for stretching out quite a lot. In some cases, where the finished object will experience a lot of wear and tear, even manual yanking can be an option.

#5 Pick the right knitting stitch pattern

And the very last thing you should observe is that you pick the right knitting stitch pattern. Typically, your pattern should tell you which stitch you should be working the gauge swatch in and it’s essential that you stick to these specifications.

Different knitting stitch patterns will have a different gauge. For example, garter stitch has a square gauge. This effect is famously used to knit mitered squares. While stockinette stitch or ribbings will typically have a row gauge that is 20-30 percent above the stitch gauge (e.g. 20 stitches x 26 rows).

This means, if you are designing your own pattern, you might have to knit multiple swatches – one for each knitting stitch pattern. Because if your knit and purl tension differs a lot, or your tension when you knit a fair isle pattern, this too could lead to a lot of disappointment.

And even for commercial patterns, this might be required because imagine your purl tension is a bit off but the designer can purl very consistently. And when the pattern transitions from stockinette stitch to a knit-purl combination, your row gauge would be off.

[Bonus tip] Measure and try on

If you ask me, gauge swatches are a nice crutch, and getting gauge is an illusion (click on the link to read why!). There are just too many variables. So please, never forget to measure your work in progress or possibly try things on. If you knit your swatch diligently, you should know how the fabric will behave after washing & blocking.

I urgently recommend trying things on – especially if it’s a fitted garment – frequently. And when you notice that your sweater in the making is already a bit looser than you’d like it to be and you know this yarn will give quite a bit after washing, then it means it’s probably better to frog things.

Waiting until you are finished before you try something on is, in my experience, one of the biggest beginner mistakes that can lead to so much grief. And just in case, here’s a list with 15 other common knitting mistakes and how to fix them.

Anyway, that’s everything you need to know about knitting gauge swatches. Comment below in case you still have any questions.