How to Crochet a Diagonal Square

Tutorial for corner-to-corner (c2c)/ diagonal box crochet

Corner-to-corner crochet, also known as diagonal crochet, diagonal box stitch and c2c, is a method of starting crochet in one corner of a square, growing it row by row on the diagonal until you reach the desired size and then decreasing back down to the opposite corner. The stitches, made with double crochet, look very similar to the granny stitch, but the way that the rows are turned and worked on the diagonal give it a slightly different, more interesting, texture.

Diagonal crochet is a...MORE historic technique that has recently been given new life, although it is more commonly called c2c today. It can be used to make a variety of square objects but is particularly popular for crocheting blankets. It is especially popular for graphghans, which alter colors in different diagonal boxes to create beautiful pictures.

Here are the instructions for diagonal crochet. You can use this free pattern to make an afghan in diagonal crochet by making one large square of the size desired or, for take-along work, you can make smaller squares (perhaps in varied colors) to join together when finished.

  • 01 of 13

    Diagonal Crochet Stitch: Step One

    Chain four
    Chain four. Kathryn Vercillo

    The first thing that we are going to do is create a short starting chain. This will be the foundation chain into which you will work row 1, which will be the first corner box.

  • 02 of 13

    Diagonal Crochet: Row 1

    How to Start Corner to Corner Crochet
    How to Start Corner to Corner Crochet. Kathryn Vercillo

    Work into the fifth chain from hook.

    Make 3 dc stitches into that chain.

    The first group of chains counts as the first dc, so you will now have one corner block consisting of four dc stitches.

    All of your blocks are going to be made from four dc stitches. This is what gives it the appearance similar to granny stitch (which is typically sets of 3 double crochet stitches).

  • 03 of 13

    Diagonal Crochet: Row 2, Part A

    How to Start Corner to Corner Crochet
    How to Start Corner to Corner Crochet. Kathryn Vercillo

    Turn your work and chain five. This will be the start of diagonal row 2.

  • 04 of 13

    Diagonal Crochet: Row 2, Part B

    How to Start Corner to Corner Crochet
    How to Start Corner to Corner Crochet. Kathryn Vercillo

    Working into the fourth chain from the make, make 3 dc stitches. Similar to Row 1, this is going to create a total of 4 double crochet stitches to make the first block of Row 2.

    Continue to 5 of 13 below.
  • 05 of 13

    Diagonal Crochet: Row 2, Part C

    C2C, Row 2, Block 2
    C2C, Row 2, Block 2. Kathryn Vercillo

    Now, locate the third and fourth dc stitches from the block in Row 1. Slip stitch into the space between those two dc stitches.

  • 06 of 13

    Diagonal Crochet: Row 2, Part D

    How to Crochet Diagonal
    How to Crochet Diagonal. Kathryn Vercillo

    Chain three. This is going to count as the first double crochet of the second block of row 2.

  • 07 of 13

    Diagonal Crochet: Row 2, Part E

    How to Crochet Diagonal
    How to Crochet Diagonal. Kathryn Vercillo

    Make 3 dc in the same space between the two dc stitches of the block in the previous row, right next to the chain three. This will give you four dc stitches in that space. This creates the second block of row 2. You now have your first corner block as row 1 and then two more blocks in row 2. 

  • 08 of 13

    Diagonal Crochet: Row 3

    How to Crochet C2C
    How to Crochet C2C. Kathryn Vercillo

    Turn your work and chain 5. This is the same thing that you did to begin Row 2 and it will be the same thing that you do to begin all of the rows while you continue to increase the size of your c2c crochet blanket.

    Continue to 9 of 13 below.
  • 09 of 13

    Diagonal Crochet: Row 3 continued

    How to Diagonal Box Crochet
    How to Diagonal Box Crochet. Kathryn Vercillo

    You already know what to do, but we'll refresh your memory with a few more practice steps. So, you're working the first block of row 3. You have already done your chain 5, so now you make 3 dc stitches into the fourth chain from the hook. This gives you your first block of 4 dc stitches.

  • 10 of 13

    Diagonal Crochet: Row 3 continued

    Crochet C2C
    Crochet C2C. Kathryn Vercillo

    Next, you will slip stitch into the space between the third and fourth dc stitches of the block in the row below. Then you will chain 3 to create the first double crochet and then 3 dc into the same space. This creates your second block of Row 3.

  • 11 of 13

    Diagonal Crochet: Row 3 complete

    Corner to Corner Crochet Stitch
    Corner to Corner Crochet Stitch. Kathryn Vercillo

    Continue working the pattern that you have established. At the end of diagonal crochet row 3, you will have three blocks.

  • 12 of 13

    Continue Diagonal Crochet

    How to C2C Crochet
    How to C2C Crochet. Kathryn Vercillo

    You will keep growing your work in the same manner, row by row. You add one new block at the beginning of each row. Each row will have the same number of blocks as the row number. (So here we are in row 5 and there are five blocks.)

    Proceed in this same manner until you are satisfied with the size of your diagonal crochet blanket. When your row is as long as you want the midline of your blanket to be, you will be ready to decrease.

    Continue to 13 of 13 below.
  • 13 of 13

    Decreasing Diagonal Crochet

    How to Diagonal Crochet Decrease
    How to Diagonal Crochet Decrease. Kathryn Vercillo

    Slip stitch in each of first 3 double crochet stitches. This is how you decrease the row by one block. That's because instead of adding a block to this corner like you normally would, you are slip stitching over to the next corner in, effectively skipping a block.

    Then slip stitch into the space between the third and fourth double crochet stitches to begin your first box of the row. Working as usual, chain three and then three dc into that space. Continue across the row as normal. You are...MORE making boxes the same way as before.

    However, when you get to the very last block, don't make the final block. Instead, make your slip stitch as you normally do. But don't proceed with the "chain 3 and three dc" that would normally go here. Instead, leave off with the slip stitch. This decreases the row by one block.

    You will then turn the work and repeat all of the steps from this section. Each row will have one less block than the previous row until you finally get to the opposite corner of where you started and have only one block in that last row!