Wednesday, 17 April 2019

My Tension Square is not the Right Size... Help!

Swatches in different stitch patterns. L to R: chevron colourwork, stocking stitch, knot pattern, moss stitch, stocking stitch

Recently, I was speaking to a knitter who told me she was having difficulty achieving the required tension for her project. “I just can’t get my tension square to come out the right size!” she exclaimed. “Help!”

A lovely swatch knitted in Rowan Cocoon shade Clay

As I talked her through various ways to address the problem, I decided it would be worth writing up a quick blog post to help out any other crafters who might be struggling with the same issue. Here’s a non-exhaustive list of things to check when you’re struggling to get gauge:
(The first 4 points apply to both knitting and crochet, but the final point is only relevant to knitting.)


  • Did you cast on enough stitches? If the tension you are aiming for is, say, 22 stitches x 28 rows, it can be tempting to cast on 22 stitches, work 28 rows, and then measure your swatch. Unfortunately, this is not a very reliable guide to your tension. One of the main reasons not to trust that piece of knitting is that the edge stitches on the sides, top and bottom are formed differently to those in the middle of the work. They are not “anchored” into place by other stitches on all sides and, consequently, they are a slightly different shape and size. A better approach is to cast on a few extra stitches (in our example, at least 30 but the more you have, the more accurate your measurements will be) and work a few extra rows. Then, measure the centre 10cm x 10cm and count how many stitches and how many rows fit into that square. This will give you a far more reliable guide to your tension and how close it is to the tension specified in your pattern.
  • Is the tension given for stocking stitch or another stitch pattern? The tension guide on a ball band will give you the expected number of stitches x the number of rows in stocking stitch, but a pattern may tell you the number of stitches x rows in a different stitch pattern, according to the stitch pattern used in the garment. This can make a big difference to the number of stitches or rows you can expect to fit into 10cm. For example, 30 rows of garter stitch (knit every row) will only be about half as long as 30 rows of stocking stitch (alternating knit and purl rows). Similarly, 20 stitches in a cable pattern will not be as wide as 20 stitches in stocking stitch, because the cables draw the fabric together. Be sure to make your swatch in the same stitch pattern as listed in the pattern!
  • Did you block your swatch? If you’re going to be blocking your finished article, or there is any chance of it stretching over time, it is best to treat your swatch in the same way in order to get as accurate a picture as possible of what your finished project will look like after you’ve washed and worn it. The tension given at the start of a pattern should take this into account, since the finished measurements are usually calculated alongside the tension requirements. So, if you block your swatch and afterwards it is 25% larger than it should be, your finished cardigan will also be 25% larger once you’ve washed it. So, to get a true idea of how big your finished object will be, you should always block your swatch!
  • For small adjustments, try a different needle material. If your tension is off by only a tiny amount, you can make very small adjustments by knitting with a different type of needle. Many knitters find their tension is slightly different when knitting with bamboo vs aluminium needles, or circular needles vs straight needles. (This also means that it can be risky to switch from one to another part way through a project, as your tension might change!) Likewise, crocheting with an aluminium hook vs a bamboo hook can make a real difference.
  • Are the stitches still “live”? Casting off, especially if you cast off quite tightly, can alter the tension of the top row of knitting, as can leaving the stitches on the needle. The solution? Slip the stitches onto a piece of scrap yarn before measuring them, or work a few extra rows and just measure the middle rows.

So, I hope this information is helpful, either to solve existing tension problems or to prevent them from happening in the first place. If you have other tension questions, feel free to leave us a comment below.