How to knit a patchwork mitred square blanket

I’ve been meaning to knit myself a mitred square blanket for years, and yet until I broke my foot last week and found myself with a load of enforced sitting down time, I have never done it.

Obviously, that has now changed. In fact, I pretty much can’t stop knitting my multicoloured patchwork delight of a blanket now – and I am very much encouraging you to do the same.

Mitred square blanket with yarn balls and mini skeins

What on earth is a mitred square?

A mitred square is a very clever little thing. You start with a big cast-on, and then work your way diagonally across. You work a 2 stitch decrease in the centre of every other row, and that pulls the stitches in to give you that square shape.

It’s way better than knitting a normal square for two reasons; first, that decrease adds a little bit of interest to the process. And second, the rows just keep getting shorter. Which is very, very satisfying.

A little note on gauge

I normally bang on endlessly about how gauge is THE MOST IMPORTANT THING and INCREDIBLY VITAL  in knitting, but I’m not going to do that here.

In fact, I’m not even going to give you a gauge.

The whole point of this blanket is that you’re using up what you’ve got to hand, so the gauge is bound to vary according to what you’re using. It’s a blanket. Using scraps. That’s fine.

Materials you need for your mitred square blanket


The whole point of this blanket is that it’s using up teeny tiny scraps of yarn – so your first step is to gather together all the bits and pieces of yarn you want to use.

For my patchwork blanket, I’m using up the leftovers from my last few years’ worth of yarn advents. They’re all 4ply/sock weight, so the instructions below are based on that. You can of course use whatever you’ve got to hand, and the construction method will be the same – but you may find you need more yarn per square, and different needle sizes/cast-on numbers.

Each of my squares uses around 25m of yarn, but to make sure I’m using up as much yarn as possible I’m knitting some striped squares in there so that I can use up even the tiniest little bits.

The amount of yarn you need depends on how big you want your blanket (more on than below) but I’d say you’d want a minimum of 20 squares worth for a baby blanket, and quite a bit more for a bigger one.


I’m using 3.75mm (US 5) 40cm circular needles. I could say this is so I’m creating a blanket that’s cosy but not too thick, but the reality is that those just happened to be the needles I had spare when I decided to cast on.

A short circular needle is pretty handy for this kind of project though; the bend of the cable works well with the angles of the square, without giving you too much cable to worry about

Notions and extras

You’ll also need a removable stitch marker or two, and a tapestry needle for darning in ends.

Knitting skills you need to knit this blanket

  • Casting on (I use the long tail and backwards loop cast-ons for my blanket – more info on that below)
  • Knit stitch
  • Double decrease – I use a centred double decrease (CDD) for my blanket. To work this stitch, slip 2 sts as if you’re going to knit them, knit the next stitch, then pass the slipped stitches over the just-worked stitch.
  • Picking up stitches
  • Weaving in ends.

Planning the size of your blanket

One of the great joys of a mitred square blanket is that you don’t have to make decisions about size at the start – but that said, it’s always nice to have a vague idea where you’re going.

The blanket is constructed by joining on a new square to the previous ones, which means two things – firstly, no seaming (hurrah!), and secondly, that your blanket can theoretically be never-ending as you can just keep adding squares forever.

Or you can just keep adding until you’re done.

Each of the squares knitted as per these instructions measures about 11 x 11 cm. I’m hoping to initially scrabble together enough yarn for 56 squares, arranged in a 7 squares by 8 squares setup – so my blanket should be about 77cm by 88cm. 

But then I can just keep adding to it every time I have enough scraps for a new row. 

Working your first square

Yep, this blanket all starts from one simple square. Which you work like this:

  • Cast on 53 stitches – I use the long tail cast-on, because it’s my favourite. Place a removable stitch marker after 26sts.
  • WS (setup): Knit one row
  • Rows 1 (RS): Knit to one stitch before marker, remove marker, work a cdd, place marker before stitch just worked, knit to end (2 sts decreased in centre of row)
  • Row 2 (WS): knit 

Repeat rows 1 and 2 until you’ve got 3 sts left. Work a final CDD, then cut your yarn, thread it through the remaining stitch and pull up tight.

Ta-da! You’ve got a square.

Adding squares to your blanket

If you want all your squares to face in the same direction, then you’ll need to add them in one of three places:

  1. To the right of a previous square to start a new column
  2. Above the left-most square to start a new row.
  3. Picked up from two previous squares (above one, and to the right of the other)
A diagram of the blanket showing where squares are joined

Exactly how you join your square varies a bit depending on where you’re joining it.

  • To join in position 1: cast on 26 sts. Pick up and knit 1 st from the bottom right hand corner of the previous square, then pick up and knit 26 sts up the right hand side of the square. Turn to the wrong side and knit one row.
  • To join in position 2: Pick up and knit 26 sts along the top edge of the square below. Pick up 1 extra st in the top left hand corner, then cast on 26 sts using the backwards loop cast-on. Turn to the wrong side and knit one row.
  • To join in position 3: Pick up and knit 26 sts along the top edge of the square below. Pick up and knit 1 st in the corner between previous squares, then pick up and knit 26 sts along the right edge of the square to the left. Turn and knit one row.

After you’ve worked these joins, you just carry on knitting the squares exactly as you did for that first square.

A note on the ends…

Unless you want to send yourself completely doolally by giving yourself all the ends to sew in at the end of your project, I thoroughly recommend darning in your ends as you go.

I know, I know, we say that about every project we ever knit, but this time it really does make sense.

I’ve just been knitting the ends into my blanket as I go (I catch them behind my stitches as I work – there’s a video tutorial on this coming soon) and it is making me feel SO much better about this as a project.

Of course, it does mean that some fellow knitting friends are a bit concerned that I perhaps hit my head when I injured my foot, because being this sensible is very out of character.

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