Corner to corner · free tool
C2C crochet calculator
Enter your piece in blocks. You get the total rows, where each phase starts and ends, and what to do on every row.
| Row | Phase | Blocks | At the ends |
|---|
How C2C rows work
Corner to corner is worked on the diagonal, one row of blocks at a time. A piece W blocks wide and H blocks tall always has W + H − 1 rows, and every row falls in one of three phases.
- Increase. From row 1 until the row has as many blocks as the short side. Each row adds a block at both ends.
- Straight. Only in rectangles. You increase at one end and decrease at the other, so the row keeps the same number of blocks while the piece grows toward the long side.
- Decrease. Until the last corner. Each row loses a block at both ends.
Here is a small rectangle, 5 blocks wide and 3 tall, row by row:
| Row | Phase | Blocks |
|---|---|---|
| 1 | Increase | 1 |
| 2 | Increase | 2 |
| 3 | Increase | 3 |
| 4 | Straight | 3 |
| 5 | Straight | 3 |
| 6 | Decrease | 2 |
| 7 | Decrease | 1 |
A square has no straight rows: a 3 × 3 square increases on rows 1–3 and decreases on rows 4–5.
Questions
How many rows does a C2C piece have?
Width plus height minus one, counted in blocks. A 40 by 50 block blanket has 89 diagonal rows. A square of 30 by 30 blocks has 59.
When do I start decreasing in C2C?
In a square, right after the row that has as many blocks as the side. In a rectangle, you first increase until the row has as many blocks as the short side, then work straight rows (increase at one end, decrease at the other) until you reach the long side, and only then decrease at both ends.
What is a block in C2C crochet?
A block, also called a tile, is the small square of stitches that C2C builds with, usually a chain and three double crochet (US) or treble crochet (UK). Patterns and graphs give their size in blocks.
Does it matter which side is the width?
Not for the row count. Swapping width and height gives the same total rows and the same increase, straight and decrease ranges.
