How to Swatch. A Step-By-Step Guide


When we're excited about a pattern and gorgeous yarn and itching to get started, knitting a swatch can feel like a chore that wastes precious yarn and knitting time. But really and truly, it's not.

Swatching might save your sweater. True.

When a designer creates their knitting pattern the first thing they do is swatch. Just like you, they knit up a square of yarn (often several squares of yarn) to work out exactly the type of fabric they want to create, to calculate how many stitches to cast on and use in the pattern and to experiment with stitches and ideas. And, every designer knits differently and most likely, differently to you.

Just like you, some knit tightly, some loosely and others somewhere in between.

  • You get to see how your yarn behaves when knitted on particular needles and in certain stitches. This is relevant if you're substituting yarn.

    Do you like how your yarn is knitting up? Maybe it's got too much drape for the sweater you've got in mind or maybe it's too stiff for the flowing cardigan?

    You might find that the stitch pattern is completely lost in the colour or blend you've chosen. 

    Knitting a little square gives you a chance to figure out whether you like the yarn for the pattern before you get started.

  • You get a chance to mimic the tension of the designer. You might already know that you tend to be a "loose" knitter or a "tight" knitter. But you don't know how the designer knits.

    Ensuring that you're using the right needles for the job means you're going to end up with a sweater that measures the size stated in the pattern.

    It's a whole lot quicker to spend an evening getting your needles right than knitting a whole sweater and finding it's too big!

  • it's a chance to try out stitches in the pattern without committing to a huge number of stitches. Daunting cables or lace panels might become less so with a little practice.

    I have found it so useful to practice stitch patterns. Several times I've changed decreases or increases to something neater after experimenting on a swatch.

I like to cast on about 40 stitches for a swatch. It gives me a chance to get in a nice rhythm without feeling like the rows are too long.

Check in the pattern whether the gauge is given for stitches knitted in the round or flat. I often do a swatch in the round and also flat.

Jane Richmond's tutorial: or Joeli's idea: are both great resources for swatching stitches in the round.

Seamless garments knitted in the round often include flat portions and many knitters find that their stitches change size when they switch from one to the other. It’s not uncommon to change needle sizes to get the same gauge knitting flat and in the round.

Knit the stitch that the designer has specified. It might be stockinette, rib or another stitch. Or maybe it's a lace or cable panel from the pattern. If you have to measure over a panel, do a couple of panels or give yourself an inch or two of stitches on either side so it's easier to measure.

Also, ensure you're using the needles you're planning to use for the pattern. Different needles knit differently.

Err on the side of too big rather than too small.

The general rule is to knit for about 6". That gives you enough knitting to get into a groove with your yarn and leave enough rows to work out your gauge.

Make sure you bind-off loosely.

It’s a great idea to check your gauge before blocking your swatch. Especially if you're using yarn that grows with blocking, like silk or superwash wool. If you know how much it grows, it'll help when you're knitting to a certain length in the pattern.

Once you've bound off your swatch, wash it exactly as you would wash your sweater or cardigan when it's finished.

I like to soak my swatches in warm water and then gently squeeze them out before laying them on a towel. Unless it's lace that needs opening up, let your swatch dry naturally without stretching it too much.

The only exception is if you're using a fibre that tends to droop like linen or alpaca. In that case, you may like to hang your swatch with a few pegs clipped to the bottom to weigh it down to replicate a heavier garment as worn.

Do you like the fabric you’ve created? Stop and check.

The fabric you've knitted will be the same as your sweater. How does it look? Are you happy with it? Does it suit the stitch pattern? Is it too tight? Too loose?

If you're not happy, consider whether it's the needles that might be the problem or the combination of yarn and pattern.

Chuck the swatch in your bag.

Think of it as taking your swatch for a test drive. See how your yarn will behave with lots of wear and tear.

How does it hold up? Masses of pilling? Super soft yarn might not be the best choice for a garment that rubs under your arms.

Is it catching on everything? Again, maybe not great for an everyday cardigan.

Think about how much wear and tear your yarn will stand and how often you’re prepared to deal with pilling.

I poke a knitting needle into each stitch to keep track of where I'm counting.

Use a hard ruler rather than a fabric tape measure and place it right in the middle of your swatch. Measure 4" or 10cm. Then carefully count every stitch. If the end of your measurement cuts a stitch in half, make sure you count that half too.

Without moving your swatch, measure the number of rows that fit into 4"/10cm.

Will your swatch wiggle into the same stitch count as the pattern? If it will without too much effort, you'll be good.

Take several measurements in a few places to double-check.

Don’t despair if your gauge doesn’t match the pattern.

You've learnt something! Imagine if you didn't swatch and didn't discover until you'd finished that you stitches were the wrong size? Your sweater wouldn’t fit.

It's great to get both stitch and row gauge the same as the pattern calls for but often, stitch gauge is the more important one to match. Row gauge can be more easily adjusted by adding more or fewer rows at various places in the pattern.

Don't take that as gospel though. If you're knitting a cardigan from side to side, row gauge will be more important! Similarly, a garment with raglan sleeves might have less row gauge wiggle room than a drop shoulder sweater.

If you're getting more stitches than called for in the pattern, try making another swatch with bigger needles. If you've got too few stitches, try going down a needle size.

If you're super close or if your stitch gauge is spot on but your row gauge is out you might find swapping needle tips will help get gauge.

Apparently, stitches knitted on wooden tips tend to be squatter than stitches knitted on metal tips. This interesting article will help you decide which needle tips would be best to try:

If you really can't get gauge and are determined to knit your garment in the yarn you've chosen, it's not impossible.

You'll just need to do a little maths to make it work. We’ll talk about that another day …

Libby Jonson