Why make a Gauge Swatch?

There’s a debate among knitters and crocheters as to whether you should do a gauge swatch. I’m in the “always do a gauge swatch” camp and also the “do as I say, not as I do” because I don’t always do them – but I can explain!

You should do a gauge swatch any time you do a large project. It gives you valuable information about

• how many stitches per inch you’re getting
• how much yarn you’re using by area
• what your finished fabric will look like.
• how the yarn washes and blocks

Let’s go over why these are important.

How many stitches per inch you’re getting is critical for making the garmet the right size. If you’re making a sweater that calls for 24sts/4inches and the garmet is 40 inches around, that’s 240 sts. If you’re GETTING 26 sts/4 inches in your gauge swatch and you cast on 240 sts, that’s only 37 inches! If you’re knitting with no ease or with negative ease, your sweater will be too tight.

How much yarn you’re using is critical if you have a limited amount of yarn with either a unique dye lot or you’re using hand-dyed that you can’t get more of. If you weigh your swatch and determine you’ve used a certain yardage – say your swatch weighs 5 grams and the yarn is 400yd/100g, you can estimate that you’ve used 20 yds for a 4 in square and your sweater is likely 2250 sq inches, that’s just over 2800 yds. Most patterns do this math for you, but if you’re modifying the pattern in any way, this is crucial.

What your finished fabric looks like is important because how terrible would it be to get halfway through a sweater and determine it’s too thin or see-through to keep going? It’s possible that the yarn you chose just doesn’t work at the gauge the pattern calls for. There’s a few options if you’re set on that yarn, including altering the pattern or picking a pattern that calls for the gauge you like.

How the yarn washes and blocks is valuable because if the yarn blocks to be half an inch bigger than it was when you knit it, that will mean that your finished item will grow after the first wash too! It might mean that your item shrinks or pills funny. You don’t want a garment that is ruined by it’s first bath.

So why don’t I do them all the time? Because it does take time to do them. I use mainly superwash wool with nylon (the typical 80/20 blend), which doesn’t tend to pill, shrink, or grow very much. Smaller items like hats, mittens, and socks aren’t affected as much by growth/shrinkage because the difference of a quarter or half a stitch per inch isn’t as noticeable. And for smaller projects, you’ll be able to see your gauge in the piece just as quickly as if you knit a swatch, and frogging it from that point isn’t as heartbreaking. I almost always buy plenty of extra yarn for the project I want or I measure my working yarn with a scale as I go so I know as early as possible if I have enough.

All that being said, I will always swatch for a sweater or blanket. Anything that will take a significant amount of time, will experience a significant amount of wear, or use a significant amount of limited quantity yarn will get a swatch.