Whenever I teach a beginners or next steps knitting class (which is pretty darn often), I start off with a simple question: do you know what gauge is?

Very often, the answer is “no”.

But gauge is one of the most important things to get your head around when you’re learning to knit – especially if you want to knit things that come out the size you expect, and use the amount of yarn that you’re told they will.

What is gauge in knitting?

Very simply put, gauge is how big stitches are. Different yarns, different needles, and different knitters all produce different size stitches, so just saying “knit this pattern with this yarn and these needles” isn’t going to cut it.

Two knitters who use the exact same needles and yarn can produce very differently sized stitches. Which is why knitting patterns give a gauge measurement alongside those yarn and needle suggestions – so you know exactly what size stitches you’re aiming for.

How is gauge measured?

The standard gauge measurement is the number of stitches and number of rows within 10cm. A pattern will say something like “20st and 28 rows to 10cm/4in” which is the golden bit of info you need to make sure your item comes out the size you want it to be.

You can get all sorts of fancy gauge measuring tools, but all you really need is a ruler or measuring tape. Place the 0 mark at the edge of one of your stitches, and count across them until you get to 10. Bam. That’s your stitch gauge. Then do the same, but counting up the rows. Row gauge sorted.

Not sure how to count stitches and rows? Thankfully I made these very classy diagrams for my beginners classes, which show you what to do.

Is gauge measured before or after blocking?

Unless your pattern specifies otherwise, always assume that the gauge is measured after blocking. The process of blocking can affect different yarns in very different ways, so stitches that started out the same size can end up diverging quite a lot once they’ve had a good soak and dry.

Superwash treated yarns in particular are notorious for growing with blocking, so while your gauge might match before you block your item, it could be very different after. And even if you decide to try and counteract this by not blocking, that’s not exactly failsafe; after all, you’re probably going to end up washing that item eventually, and at that point the yarn is going to do that stretch and you’ll end up exactly where you were trying to avoid being.

(If you want to know more about blocking, Meg at No Frills Knitting has written a top notch guide to it)

Why is gauge so important for my knitting?

The size of your stitches is what determines how big your finished item is going to be – so you want to make sure that your 100sts is the same size as the designer’s 100sts, otherwise you can end up with something that’s a totally different size from the one you expected.

Think of it like Lego and Duplo (why yes, I have spent quite a lot of my time with those Danish bricks this summer). You can build two things that look the same – one in Lego, and one in Duplo – with the exact same construction and number of blocks, but one of them is going to be a hell of a lot bigger than the other, because Duplo bricks are a hell of a lot bigger than Lego ones.

Gauge is like that.

It’s also very important to understand if you want to make any alterations to a pattern- knowing the gauge means you know how many stitches or rows you want to add or remove to make, say, a 2in/5cm change to your pattern.

But my project is a shawl, so I don’t need it to fit. Surely gauge doesn’t matter for that?

Sorry to break it to you, but it kind of still does. Sure, it’s not as important as it is for getting something like a well-fitting knitted sweater, but if you find yourself straying too far from the gauge then it’s pretty likely that you won’t have the right amount of yarn.

After all, if gauge is about how big your stitches are, and your stitches are much bigger than the pattern suggests…well, stands to reason that they’re going to be using up more yarn, and so you could run out. And running out of yarn is the pits.

Having a whole load left over isn’t magnificent either, which is the other risk here. But at least you can do other things with that yarn.

How do I check my gauge?

You knit yourself a little gauge swatch is what you do. I’ll write a big old blog on this soon, but the basic are:

⁃ check how many stitches there are to 10cm in the pattern you’re looking at. Cast on that many, plus 6 more (this means you don’t have to include curly edges in your measurements)

⁃ Check what stitch pattern the pattern says the gauge is over

⁃ Knit for about 10cm in that pattern.

⁃ Cast off. Block your swatch (Basically, get it wet, then dry it flat).Measure it.

If your gauge is coming out at what the pattern asks for, then congratulations, because you’ve won the knitting jackpot. If it isn’t, then try again with a different needle size, following this basic rule:

⁃ if you’ve got too many stitches, they’re too small, so try a needle size up

⁃ If you’ve not got enough stitches, they’re too big, so try a needle size down.

Rinse and repeat as many times as required until you’ve got the gauge you need.

What if I can get the stitch gauge, but not the row gauge?

Panic not! This is a surprisingly common dilemma, but generally speaking, the stitch gauge is the one that’s more important. Often patterns will tell you to knit til your work measures, say, 8in/20cm, which means a slightly off row gauge doesn’t matter too much because you’ll be measuring, not counting.

There are some exceptions to this rule, but generally speaking your pattern is going to tell you if your row gauge is really that important. And if it is, and you’re really struggling, then there might be tricks you can do when blocking to make that work better.

So there you have it. Gauge demystified.

Got any more questions? Drop a comment below.