How to read a C2C crochet graph, and how big and how much yarn
The short answer
A C2C (corner-to-corner) graph is worked in diagonal rows. Right-handed, you start with one square in the bottom-right corner, add a square at each end of every row until you reach the edges, then decrease back to the opposite corner. Odd rows are read from their lower end up, even rows from the top down. In worsted yarn each square is about 2.5 cm, so a 50 × 60 inch lap throw is about 51 × 61 squares.
A C2C graph looks like any other colour chart: a grid of coloured squares. The difference is how you move through it. You do not work across in straight rows. You work diagonally, one small block of stitches for each square, from one corner to the one opposite. Once that clicks, a C2C graph is one of the easiest charts to follow.
What a square is
In C2C, each square on the graph is one tile: usually a chain of three and three double crochets (US terms), or treble crochets in UK terms. Tiles sit at an angle and lock together, so the fabric grows as a diagonal wedge from the starting corner.
Because a tile is roughly square, one tile per square is true to the picture. That is why C2C suits photo blankets: the image does not stretch the way it can in single crochet.
Reading the rows
For a right-handed crocheter:
- Row 1 is the single square in the bottom-right corner.
- Row 2 has two squares: the one above row 1 and the one to its left.
- Each row adds one square at each end, so the diagonal grows.
- At the edges, the rows stop growing on that side and start to shrink. On a rectangle, one side reaches its edge first, so for a while you increase on one end and decrease on the other.
- The last row is the single square in the top-left corner.
Direction alternates. Odd rows are read from their lower end upwards; even rows from the top end down. That matches the way the work turns at the end of each row.
Left-handed, mirror everything: start bottom-left and finish top-right.
Written rows beat counting squares
The hard part of a C2C graph is not the stitch. It is counting diagonal squares on a screen or a printout without losing your place. A written row does the counting for you: “Row 23: 4 blue, 2 white, 7 blue.”
The C2C graph generator turns a photo into a graph with every diagonal row written out in words. Choose Start stitching and the tracker shows the row you are on, moves one colour block per tap, warns you when a colour change is coming, and remembers where you stopped. Send it to your phone with a private link that carries the chart, never the photo. The photo is read and charted in your own browser and is never uploaded.
How big should it be?
Size in C2C comes from the number of squares and your yarn. In worsted yarn, a square is about 2.5 cm or one inch.
| Blanket | Size | Squares in worsted | Yarn, with 15% extra |
|---|---|---|---|
| Baby blanket | 30 × 36 in (76 × 91 cm) | 30 × 37 | about 1,530 yd |
| Lap throw | 50 × 60 in (127 × 152 cm) | 51 × 61 | about 4,290 yd |
| Twin | 66 × 90 in (168 × 229 cm) | 67 × 91 | about 8,410 yd |
| Queen | 90 × 90 in (229 × 229 cm) | 91 × 91 | about 11,430 yd |
These are the figures the tool’s own size guide uses for worsted yarn. The page lists the same sizes for DK and chunky yarn too.
Thicker yarn makes bigger squares, so you need fewer of them for the same size, and the picture has less detail. For a portrait of a pet or a person, 60 to 80 squares across keeps the face recognisable. A name or a simple logo reads well at 40 to 50.
If you are unsure, start with a 30 × 30 cushion. It tests the colours and your tension in a weekend.
How much yarn?
A worsted C2C square uses roughly 1 to 1.5 yards of yarn. The tool estimates 1.2 yards per square and adds 15% for tails and joins. On that basis:
- A 30 × 30 cushion is 900 squares, about 1,250 yards.
- A 51 × 61 lap throw is 3,111 squares, about 4,300 yards.
Tension varies more than most people expect. For a better figure, make one square, unravel it, measure the yarn, and enter your own number in the tool. The estimate is split by colour, so you know how much of each to buy.
How many colours?
Usually 5 to 10. Every colour is another yarn to buy and more ends to weave in. Past about ten, the extra shades mostly add scattered single squares rather than detail. Start at eight and merge any colour with only a few squares into its neighbour. The tool’s clean-up setting removes lone squares for you.
Related guides
For single-crochet graphghans, the guide to turning a photo into a crochet pattern explains why square-grid charts stretch faces and how to avoid it. For keeping count as you go, see how to keep track of rows, or use the row counter.
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