What Is Knitting Gauge and Why Is It So Important?

Simply put knitting gauge or knitting tension depending where you live, is a sample of your knitting to find out how many stitches you get in one inch. 

And you do this by knitting a gauge swatch also known as a tension square.

What a Knitting Gauge Swatch Looks Like

Knitting Gauge

Pretty boring right?

But ..by knitting this little tension square it will help you match the knitting tension you have with the gauge in your knitting pattern. 

This is what it will look like in a knitting pattern:

Gauge 18 sts and 24 rows = 4 ins (10cm) with size 8 (5 mm) knitting needles in stockinette st.

It is also listed to give you the freedom to choose another yarn if you don't like the one in the pattern or you just want to try something else.

If you want to substitute a yarn in your knitting pattern check the yarn label to make sure that it matches the knitting gauge in your pattern.

Then make a swatch with your new yarn instead.

Note: Just because the knitting pattern suggests certain knitting yarns and needles it doesn't mean you have to use them. 

What is important is matching your knitting gauge to the pattern and if that means using a different size needle then go for it.

OK but Why is Knitting Gauge so Important?

Knitting gauge

Because the size of the stitches matters a lot.

When you knit anything with shape like sweaters for instance, you want to knit the right size so it will fit.

If your knitting is even off by half a stitch it could mean a sweater ends up being way too big or way too small. 

Here's an example:  You want to knit a sweater that is 40 inches around. The knitting gauge says you need 5 stitches per inch. With the correct gauge you can cast on 200 stitches and make your sweater.

(40 inches multiplied by 5 stitches per inch equals 200 stitches to cast on) This is the formula for knowing how many stitches you need on your needle.

(Inches X stitches per inch)

You don't bother checking your knitting gauge and end up knitting with 4.5 stitches per inch instead. 

But you still cast on 200 stitches and knit your sweater.  When you finish you will actually have a sweater that is 44.45 inches not 40 inches.

(200 stitches divided by 4.5 stitches per inch equals 44.45 inches) This is the formula for knowing how many inches are in a specific area of knitting (and only if you know your knitting gauge)

Okay you may not mind a nice loose fitting sweater but what if it was the other way around and it ended up being 4 inches too small - hmm I wonder if it would stretch.

You see I've been there more times than I'd like to admit. I really know.

Checking the knitting gauge beforehand and switching to a smaller knitting needle could have saved the disappointment.

Why take the chance when it is so easy to adjust in the beginning?

What Does a Gauge Swatch tell you?

Many things, you see a lot of things affect gauge like:

  • Yarn weight
  • Knitting needles (sizes and material of needle)
  • Stitch patterns - ribbing for instance goes in more like elastic when its knitted up
  • How tight or loose you knit
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By knitting a swatch you can find out a great deal about the yarn itself and also about how you knit, things like:

  • If your yarn and needles match up to the knitting gauge in your knitting pattern
  • How well your stitch pattern shows up with the yarn you are using
  • Whether the color combination you chose works well
  • How tight or loose you knit. (This way you can adjust the needle size)
  • How easy the yarn is to work with. Some yarns look beautiful but are very difficult to knit with
  • A way to test and practice new stitches
  • Give you inspiration and ideas

Are There Projects That Don't Need Knitting Gauge?

Yes. You can find lots of things: wash cloths, blankets, some knitted bags, afghans and scarves don't necessarily need a gauge.

What Do You Do With all the Swatches? (Seems like a waste)

I know how you feel because I thought that way too but then knitting a sweater that doesn't fit is a waste of time too. And disappointing. 

There are some things you can do with that swatch (or swatches).

You can frog (unravel) it and use the yarn in your knitting project or save it and use it with something else. 

Or, you can save a bunch of swatches and when you have enough you can sew them up into a small blanket or throw, even a scarf.

Gauge swatches actually are a nice pocket size so if you're knitting a sweater you could use your swatch for a pocket.

Create some swatch cards.  Pick up some recipe cards or something like it and write down all the knitting information you learned from that yarn.

Things to write down on your swatch cards:

  • Name of yarn
  • Color
  • Fiber
  • Needle size used
  • Stitches per inch
  • Rows per inch

Then mark down any notes you have or things you made with it. Punch a hole in the card and attach it to your swatch and store it. Have a file for all your knitting projects.

There are probably more things you can do too. Have any ideas?

Knitting gauge swatch

Here's something I did with one of my swatches...

May seem a little silly but....I had a small plastic ice cream container and I was using it for my small knitting tools. 

So I wrapped my swatch around it and made a little container cozy...haha. 

At least it looks prettier than the plastic container right? 

How Do You Knit A Gauge Swatch?

First, check to see what the knitting gauge is in your pattern. So let's say it says:

18 sts and 24 rows = 4 inc (10 cm) with size 8 (5mm) needles in Stockinette st.

What this means is there should be 18 stitches and 24 rows in those 4 inches.

To start, use the same yarn and needles the pattern calls for and cast on about 20 stitches and knit Stockinette stitch for about 5 inches. Make sure to bind off your stitches too.

If you want to add a garter stitch border you can but it's not necessary.

There is some controversy over blocking your swatch. Here's my thought about it.  I will block my swatch when the fit is crucial like sweaters.

However for things like mittens, hats, scarves and shawls, if I'm using acrylic yarn I won't bother.  

What Do You Need To Measure Knitting Gauge?

All you need is a stitch gauge or a plain ruler. I also use a calculator because I am terrible with fractions so I keep a little one in my knitting bag.

Measuring Your Knitting Gauge Swatch

Knitting gauge

Lay your swatch out on a flat hard surface (not on your lap) and put your stitch gauge over your swatch without stretching the stitches in any way. 

Then you just count those little V's. Each 'V' is one stitch.

Count the stitches across and then count how many stitches are in the rows as well.

Here's is a closer look at the stitches

Here's a closer look at the knitting gauge.

Knitting gauge

Before I take the stitch gauge off (and this isn't shown), as an extra security, I measure 4 inches along the top of the stitch gauge (outside the little slot ).

Checking your gauge along 4 inches can give you a more accurate measurement.

And that's it. Now you know how many stitches per inch you have and can check it with the knitting gauge in your pattern.

Knitting Gauge Knitting Video

Marly Bird has a great video on knitting gauge and I thought you'd enjoy it. She explains everything perfectly.  And you may even enjoy knitting the shawl she describes in her video too.

Hope this helps. Happy Knitting!