What Is C2C Crochet
Corner-to-corner (C2C) crochet builds a fabric diagonally — you start at one corner, increase one tile per row until the piece reaches its widest point, then decrease one tile per row back down to the opposite corner. The result is a rectangular (or square) fabric made entirely of small square tiles.
Each tile is a cluster of 3 double crochet stitches worked into a chain-3 space. Tiles stack next to each other in rows that run diagonally across the piece. This creates a grid-like fabric with a distinctive texture that is different from traditional row-by-row crochet.
C2C is enormously popular for graphghans — blankets with pixel-art designs worked in multiple colors. Each tile acts as one pixel, making it straightforward to translate any grid-based image into a crochet pattern. The technique is also used for solid-color blankets, baby blankets, scarves, and cushion covers. It works up relatively quickly because double crochet stitches are tall, and the tile structure means you are always working in chain spaces rather than individual stitches.
How C2C Increases Work
The increase phase builds the fabric from a single tile to the widest diagonal row. Each row adds one tile at the beginning, making the diagonal one tile wider than the previous row.
Row 1: 1 tile (the starting corner) Row 2: 2 tiles Row 3: 3 tiles Row 4: 4 tiles ...and so on.
To start a new row, chain 6 (this creates the new tile's chain-3 base plus a chain-3 turning chain). Work 3 double crochet into the 4th chain from the hook — this is your first tile of the new row. Then slip stitch into the chain-3 space of the tile below, chain 3, and work 3 double crochet into the same space. Continue across the row, working each tile into the chain-3 space of the tile below it.
For a square blanket, you increase until the diagonal row count equals the number of tiles on one side. For a rectangular blanket, you increase until the row count equals the shorter side, then work several rows at the same width (neither increasing nor decreasing) before starting the decrease phase. The C2C Calculator on fibertools.app tells you exactly when to stop increasing based on your target dimensions.
How C2C Decreases Work
The decrease phase tapers the fabric back to a single corner tile. Each row starts one tile in from the previous row's edge, effectively removing one tile at the beginning of every row.
To decrease, do not chain 6 at the start of the row. Instead, slip stitch across the top of the first tile (across the 3 double crochets and into the chain-3 space), then chain 3 and work 3 double crochet into that space. This positions you one tile in from the edge. Continue across the row normally. The result is a row with one fewer tile than the previous row.
The last row of the decrease phase is a single tile — the opposite corner from where you started. Fasten off and weave in the end. The finished piece should be a clean rectangle (or square) with pointed corners formed by the diagonal construction.
Common mistakes during decreases include accidentally slip-stitching into the wrong space (skipping the chain-3 space and going into the double crochets) or forgetting to slip stitch far enough across. Count your tiles at the end of each decrease row to catch errors early.
Calculating Size and Gauge
The finished size of a C2C piece depends on two factors: the number of tiles and the size of each tile. Tile size is determined by your yarn weight, hook size, and tension.
To find your tile size, make a small C2C swatch of about 10 tiles across and measure. Divide the width by the number of tiles to get the size of one tile. Standard tile sizes at common gauges:
Worsted weight with US H/8 (5.0 mm) hook: approximately 1 inch per tile Worsted weight with US I/9 (5.5 mm) hook: approximately 1.1 inches per tile Bulky weight with US K/10.5 (6.5 mm) hook: approximately 1.3 inches per tile DK weight with US G/6 (4.0 mm) hook: approximately 0.85 inches per tile
For a 50×60 inch throw blanket at 1 inch per tile, you need approximately 50 tiles wide and 60 tiles long. The total number of diagonal rows is calculated as: (width tiles + length tiles - 1). So a 50×60 blanket has 109 diagonal rows — 50 increase rows, 9 rows at full width, and 50 decrease rows.
The C2C Calculator handles this math automatically. Enter your target finished dimensions and your tile gauge, and it outputs the exact increase rows, decrease rows, even rows, and total yarn estimate.
Frequently Asked Questions
What stitch is used in C2C crochet? The standard C2C stitch is a small square tile made from 3 double crochet stitches worked into a chain-3 space. Each tile is connected to the tile below it by a slip stitch into the previous row's chain-3 space. The chain-3 and 3 double crochets together form one pixel-like square.
Can I use C2C for graphghans? Yes — C2C is one of the most popular graphghan techniques because each tile represents one pixel. Use graph paper, a spreadsheet, or a pixel art app to plan your design. Each cell in the grid corresponds to one C2C tile in a specific color.
How do I change colors in C2C? Start the new color on the last yarn over of the last double crochet in the current tile. Drop the old color and pull through with the new color. For designs with frequent color changes, carry the unused color loosely along the back. For large single-color sections, cut and rejoin to keep the back neat.
How long does a C2C blanket take? A standard throw-size C2C blanket (approximately 50×60 tiles) takes most crocheters 20-40 hours depending on speed and yarn weight. Graphghans with many color changes take longer due to the extra time managing bobbins and weaving in ends.