How to knit and measure your “gauge”

In this post, I’m going to talk about “gauge” and specifically, how to use a gauge swatch to measure your gauge.

Why is “gauge” important?

The pattern will describe the “gauge” the designer used.  This simply means the number of stitches and rows in a specified measurement.  Gauge is normally measured over either 4″ or 10 cm.

Everyone knits in a slightly different way.  For example some people knit more tightly / loosely than others.  That means that two people who knit the same number of stitches and rows using the same yarn may come out with a different size swatch.

Gauge is important when you are knitting something that is going to be fitted (like a cardigan / jumper, etc) as if you knit to a different “gauge” then your final measurements will be different from those that the designer intended.

How to work out your gauge

The only way to do work out your gauge reliably is to knit a swatch.

A designer/ your pattern  may say that the gauge is:

  • 18 stitches and 22 rows in 10cm/4″, using 4mm needles, in stockinette stitch.

To make sure you are on the same gauge as the designer you will need to work out if you knit the same number of stitches and rows as the designer in the same space.

It’s common (but not always the case!) that designers express gauge in stockinette stitch as it is so simple to count rows and stitches using this stitch.

Gauge will be impacted by yarn weight (size) and needle size.

How to knit a swatch

To knit your swatch, cast on your stitches, using the needle size recommended by the pattern, knit, using the recommended stitch until it is as big as you need it to be to measure your gauge, then cast-off.

Knitting a swatch can be a pain in the backside because you just want to get on with the actual pattern!  Trust me, its worth doing it, otherwise you’ll cast off that beautiful cardigan / hat / whatever only to find out its wasted effort as it is too big or too small!

My tip for casting-on

When you are knitting a swatch, cast on more stitches and knit more rows than you need.  For example, if you have to measure 18 stitches and 22 rows, cast on 25-30 stitches, to allow yourself room to count the stitches.

Stockinette swatches will curl at the edges and so you need space to be able to count the stitches properly.  You might also want to count the stitches / rows in your swatch in a few different places to make sure your gauge it is consistent.

My tip for counting stitches

Don’t forget that 1/2 or 1/4 stitches will count when you are measuring your gauge.  For example, if you are 1/2 a stitch out over an 18 stitch sample, when you cast on 100 stitches you will be several stitches too big or small.

Don’t forget to “block” your swatch

If you’re making something which is going to be washed, like a cardigan or jumper, I advise that you wash and block (see here if you’re not sure what blocking is) your swatch.  I find that with some yarn, the fabric will “relax” when washed and so your gauge will be different.

How to adjust your gauge

So, you’ve knitted your swatch and its not right. What can you do about it?

Go up or down a needle size

The simplest way is to change the size of your needle until you can knit at the same gauge as the designer.

  • If you have more stitches and rows then the designer specifies, try going up a needle size (or two/three)
  • If you have fewer stitches and rows than the designed specifies, try going down a needle size (or two/three).

Don’t go up or down too many needle sizes as if you get too far away from the needle recommended by the yarn your fabric will start to become too loose.  A couple either way should be OK though!

Try a different yarn

If changing needle size doesn’t work, maybe the yarn isn’t right.  Try a different yarn.

As I explained in this post, a yarn may be called the same “weight” but is actually thicker or thinner.

The purple and grey yarns on the right of this picture are both “Super chunky” but the grey one is a lot thicker!


Knit a different size

The final, and most complicated way (for if all of the above methods don’t work!) is to knit a different size to the one you think you should based on your measurements.

To do this, you will need to calculate how many stitches / rows per 10cm/4″ you have and then work out, if you knitted the same number of stitches as the pattern recommended, what size your garment will be.

You will then know how big it is supposed to be, how big it actually will be and you can then work out which size you need to knit to get it to be the size you want.

Example of knitting a different size

That’s hard to explain, so I’ll try to use an example….for my Everything Nice Hoodie, I couldn’t quite get to the gauge, so I decided to knit a different size.

  • The pattern gauge was 16 sts/22 rows = 4 in/10cm in stockinette stitch with US 8/5mm needles
  • Before washing my swatch, I was spot on with my gauge, but after washing my swatch, my gauge was 15sts per 4”.
  • The finished garment size that I wanted to make was either the 39” or 40.5” one.

Step 1 – work out a conversion factor

To work out my “conversion factor” I divided the number of stitches in my gauge (15) by the number of stitches in the pattern gauge (16).

15/16 = 0.938

Step 2 – look at how many stitches you should cast on for your size

I looked at the sizes above and below to see how many stitches the pattern says to cast on.  By multiplying those stitches by my conversion factor (0.938) I could calculate how many stitches I’d need to cast on to get something the same size using my gauge

  • The 40.5” (1X) requires a 164 Cast-On (CO), converted to my gauge  this would be a 153 CO (164 x 0.938=153)
  • The 39” (L) requires a 158 CO, converted to my gauge this would be a 148 CO
  • The 36” (M) requires a 146 CO

Step 3 – choose the closest size to the number of stitches you need to cast on

Unless you want to convert the pattern the whole way through, I recommend knitting the closest size to your gauge.

I decided that I wanted the final garment to be the 39″ pattern size.  Using my gauge conversion, that would be 148 stitches Cast-on.  The size with the closest number of cast-on stitches was a size “M”, requiring a 146 cast-on.  So I knitted that one.

Step 4 – Get knitting!

Once you have done this complicated maths to get you started, and picked a pattern size, just follow that pattern size for the entire garment.

That’s it really!

Good luck with your next project! 🙂




12 Responses

  1. I love the expediency of knitting sleeves as swatches. Though it does sometimes mean you’re ripping out a partially completed sleeve and starting over.

    I also love knitting shawls where size isn’t super important and so I don’t have to swatch. 😉

  2. So helpful, I’m definitely sharing this with my best friend, I just converted her to knitting! Also, I don’t know if you’ve seen those but now the craft stores sell gauge rulers, which are a 10cmx10cm square, you just put it on your swatch and count how many stitches/rows you have inside the square. Magic! Thanks again for sharing!

  3. I was with you, right up to the moment the maths started. I think if changing needle size or yarn didn’t work, I would just take it as a sign that I’m not meant to make that particular item!

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