C2C Increases and Decreases: Where the Turn Happens

The turn is not in the middle of the blanket. It is on the row where your work reaches the shorter side of the graph, and on a rectangle it happens in two stages, several dozen rows apart. Miss the first one and you get a diamond; miss the second and you get a bigger diamond.

Everything below is US terms, and a block means the usual chain-3 plus 3 double crochet cluster — one square of the graph.

A C2C project has three phases

Work a corner-to-corner piece and the block count per row does three things in sequence: it rises, it holds level, and it falls.

• Increasing. Every row adds a block at both ends. Row 1 has one block, row 2 has two, row N has N.
• Steady. Every row adds a block at one end and drops one at the other. The count does not change. This phase only exists on a rectangle.
• Decreasing. Every row drops a block at both ends, down to one block in the far corner.

On a square graph there is no steady phase at all — you go straight from increasing to decreasing, and the widest row is the halfway point. On a rectangle the steady phase is what makes it a rectangle rather than a square. That is the entire shaping story; the rest is knowing which row is which.

The arithmetic: which row turns

For a graph W blocks wide by H blocks tall:

• Total rows: W + H − 1.
• Increase phase: min(W, H) rows. The last of them is the widest row, and it has min(W, H) blocks.
• Steady phase: exactly |W − H| rows. Zero if the graph is square.
• Decrease phase: min(W, H) − 1 rows.

Check the arithmetic: min + |W − H| + min − 1 = W + H − 1. It always closes. The crochet blanket calculator prints all three phase boundaries for any size.

Two worked examples, because this is the kind of thing that only lands with real numbers.

A 60 × 60 square. Total 119 rows. Rows 1 to 60 increase, and row 60 is the widest at 60 blocks. There is no steady phase. Rows 61 to 119 decrease, 59 of them, ending on a single block.

A 100 × 60 rectangle. Total 159 rows. Rows 1 to 60 increase, reaching 60 blocks. Rows 61 to 100 hold at 60 blocks — that is 40 rows, which is exactly 100 − 60. Rows 101 to 159 decrease at both ends, 59 of them.

Two things fall out of this that are worth having in your head before you start. The widest row is only ever as wide as the shorter side of the graph, no matter how long the blanket is. And the two shaping changes are |W − H| rows apart, which on a long, narrow blanket is most of the project.

Side and direction also alternate every single row: row 1 is the right side, row 2 the wrong side, and the working direction reverses each time. That does not change the shaping, but it does mean "the end where I increase" is physically the other end of the work from where it was on the previous row — which is why counting blocks beats trying to remember which end is which.

Starting: the first block

Chain 6. Double crochet in the 4th chain from the hook and in each of the next 2 chains. That is row 1: one block, three double crochet with a chain-3 standing in for the first stitch.

If your first block looks like four stitches, you have counted the turning chain as a stitch as well as working three double crochet. It stands in for one — chain-3 plus 3 dc is four "posts" and one block.

Working an increase row

Chain 6, turn. Double crochet in the 4th chain from the hook and in the next 2 chains — that is your new corner block, and it is the block that makes the row longer.

Then, for each existing block in the row below: slip stitch into the next chain-3 space, chain 3, and work 3 double crochet into that same space. Repeat to the end of the row.

So an increase row is one new block plus one block worked into every block of the previous row. If the previous row had 12 blocks, this one has 13.

Change colors on the final yarn-over of the last double crochet of a block, so the new color is already on the hook when you chain 3 for the next one. Whether you carry the old color along or work from bobbins is the other real decision here, and it depends on how many color changes per row your graph has — a busy row with eight changes is a bobbin row.

Working a decrease row

A decrease row starts by giving a block back rather than adding one.

Turn without chaining 6. Slip stitch across the tops of the first 3 double crochet and into the chain-3 space of the next block. Chain 3, work 3 double crochet into that space, and then continue across the row exactly as you would on an increase row — slip stitch into the next chain-3 space, chain 3, 3 double crochet, repeat.

At the end of a decreasing row you simply turn; you do not add a corner block. If the row is decreasing at both ends, that combination — slip-stitching past the first block, not adding one at the end — is what takes two blocks off the count.

The slip-stitching-across part is the bit that feels wrong the first time. You are travelling over stitches you already made without adding height, and it looks like you are undoing something. You are not; you are moving the start of the row inward by one block.

The phase everyone gets wrong

On a rectangle, the middle of the project is neither increasing nor decreasing — it is both, one at each end, on every row.

Once one end of the work has reached the short side of the graph, that end can't grow any further, so from that row on it decreases every row. The other end keeps increasing every row until it reaches the long side. Net effect: the block count stays flat, and the piece stops growing as a triangle and starts sliding sideways as a parallelogram-ish band. That is the fabric becoming a rectangle.

This is where most first rectangles go wrong, and the failure is silent: you keep increasing at both ends because nothing tells you to stop, the block count keeps rising, and forty rows later the shape is a diamond that no border will rescue. The tell is arithmetic, not appearance. If your graph is 100 × 60 and you are on row 75 with 75 blocks in the row, you missed the turn at row 61.

Checking yourself as you go

Count blocks at the end of every row and compare it to what the row should be. It takes ten seconds and it is the only reliable check — the fabric is diagonal and stretchy and does not look wrong until it is very wrong.

That is exactly what written row-by-row instructions give you. Each row of a pattern from the C2C crochet pattern maker prints its own block total, and the corner note lands on the one row where the shaping changes:

← Row 59 [RS]: (Cream) x 12, (Teal) x 47 (59 blocks)
→ Row 60 [WS]: (Cream) x 11, (Teal) x 49 (60 blocks)
← Row 61 [RS]: (Cream) x 11, (Teal) x 48 (59 blocks) — Corner: start decreasing on RS

The (59 blocks) at the end of a line is the number you count against. The corner note appears once, on the row where the shaping turns, and on a rectangle there is an earlier one where the steady phase begins. The rows are computed from the graph, so the turn lands where the graph actually turns, not where a transcriber thought it did.

For the hands-on version — someone working an increase and a decrease on camera, slowly — the video teachers are better than any written description, including this one. Bella Coco and The Crochet Crowd both have thorough C2C walkthroughs, and Sarah Maker writes the photo-tutorial version. Watch one, then come back for the arithmetic.

If you are still deciding whether C2C is the right technique for your design at all, graphghan techniques compared covers the alternatives. And when the last row is done, the stepped edges need a border.