Crochet chart generator
Draw any round and watch it add up. Type your own counts and the chart redraws, one mark per stitch, forks where the increases fall. It runs in your browser; nothing is uploaded and nothing is kept.
| Rnd | Count | Change | What you work |
|---|---|---|---|
| 1 | [6] | — | 6sc in a magic ring |
| 2 | [12] | +6 | 6inc |
| 3 | [18] | +6 | 6inc, 6sc |
| 4 | [24] | +6 | 6inc, 12sc |
| 5 | [30] | +6 | 6inc, 18sc |
| 6 | [36] | +6 | 6inc, 24sc |
Marks run from the top of each ring, clockwise, one per stitch.
Draw a round from its counts
Type the stitch count of each round and the chart redraws: one ring per round, one mark per stitch on it, and a forked mark wherever an increase falls. The number of forks on a ring is that round's count minus the round before it, so the drawing is the arithmetic rather than a picture of it.
The arithmetic, round by round
Three operations cover every round this tool draws, and they are the same three the patterns on this site use: sc takes one stitch and makes one, inc takes one and makes two, dec takes two and makes one. Every round is therefore decided by one subtraction — this round's count minus the round before it.
| The round | What it needs | Worked |
|---|---|---|
| Gains stitches | The gain cannot be larger than the count you are working into — there are only that many stitches to put increases in. | 12 to 18: 6inc, 6sc |
| Holds its count | Nothing. Every stitch is worked once. | 18 to 18: 18sc |
| Loses stitches | Each decrease eats two stitches, so a round cannot fall below half the count before it. | 24 to 18: 6dec, 12sc |
The first round is the exception: its stitches go into a magic ring rather than into a round below, so it is written as its own count and nothing constrains it. Where a round you type breaks one of the two rules above, the tool names the round and says which limit it crossed rather than drawing something that cannot be worked.
Those strings are the vocabulary scripts/validate.py reads — sc (1,1), inc (1,2), dec (2,1) — which is why the copy button hands you lines you can paste beside a pattern and check.
Flat, a wall, or a ruffle
Under the chart the tool says one thing about the shape, and it is not a guess. It is a port of check_flat_disc() from .claude/skills/pattern-quality-gate/geometry-check.py, which is stage 3 of the gate every pattern on this site passed before it was published. It knows three things:
- A circle stays flat while each round gains exactly what the opening ring holds. Six in the ring, six a round.
- A run of rounds that hold their count is a wall. One straight round mid-piece is shaping; two in a row are sides, and the piece is a bowl or a tube rather than a coaster. A piece that tapers back in is allowed a longer pause at its widest, because that is what a leaf or a petal does.
- Gaining more than the opening ring, twice or more, puts in more stitches than the edge can take. The edge has to go somewhere, and where it goes is up: the piece ruffles.
It refuses the question outside what it was calibrated on: fewer than four rounds, or an opening ring outside four to twelve stitches, and it says nothing rather than something it cannot stand behind. It also says nothing at all about how the finished object looks. No arithmetic can. Whether a dome is the right dome, whether the fabric drapes, whether the thing is worth making — those need somebody with it on a hook.
That read is about shape. What the counts come to in centimetres is a different question and a different instrument: the gauge calculator turns a round of 36 into a measurement, at your gauge rather than at a model's.
Nothing is uploaded and nothing is kept
This page is a file. The counts you type are held in the tab you typed them in, the chart is drawn there, and the two files it saves are built there too — there is no server behind this site to send anything to, and nothing here writes to your browser's storage. Close the tab and the counts are gone with it.
There is no account, no sign-up and no export limit. The PNG and the SVG carry the chart, the bracket line and the key, with nothing written across them. If you want a row counter that remembers where you were, there is a separate iPhone app with one; the chart does not need it.
What this is not
This draws a piece worked in the round in a spiral, from its stitch counts. It does not take an image and turn it into a grid, so if you came looking for a tapestry, mosaic, pixel or filet chart — the square grid where one cell is one stitch and the colours make the picture — this is the wrong instrument and there is no point pretending otherwise. That is a separate tool and it is not built yet.
Nor is what comes out of here a pattern. A pattern names the yarn, the hook, the pieces and how they go together, and says what the thing is; this hands you one piece's counts drawn and checked for the two ways a round can be impossible. The 113 patterns in the library are the other thing.
Reading a chart somebody else drew
The marks here are the standard ones, and a chart from a magazine or a Brazilian gráfico uses the same idea — one symbol per stitch, read in the order you work them. Reading a stitch chart sets a round beside its own written rounds so the two can be read against each other. If the problem is the other way round — the chart is fine and your count is not — keeping count is where the missing stitch gets found.