Gauge calculator
Crochet a small swatch, count the stitches across 10 cm, and see how the finished piece will come out against the pattern’s size.
Measure a swatch
Work a small square in single crochet at the tension you actually crochet at, lay it flat without stretching it, and count. Ten stitches measured across is enough; twenty is steadier. Leave the round box empty and the round height falls back to the model, and the table says that it did.
12% larger than the ~11 cm Acorn and oak leaf states, tall including the stem.
Your gauge
| Measurement | Yours | The model |
|---|---|---|
| One stitch, cm across | 0.625 | 0.560 |
| One round, cm tall modelled, not measured | 0.500 | 0.448 |
The other way round
A pattern from this site, at your gauge
| Dimension | At your gauge | At the model |
|---|---|---|
| The acorn worked flat, cm across 36 stitches ÷ π | 7.2 | 6.4 |
| The same round as a tube, cm around 36 stitches in a circle | 22.5 | 20.2 |
| The acorn, cm tall 25 rounds stacked | 12.5 | 11.2 |
| Every piece stacked, cm 29 rounds in the whole pattern | 14.5 | 13.0 |
| The acorn laid out in a line, cm 540 stitches end to end | 337.5 | 302.4 |
The record's own sentence, unedited: “~11 cm tall including the stem, ~6.5 cm across the cap; the leaf about 5 cm long” — and every figure in it carries the same ~, for the same reason.
What your own gauge does to the numbers
Count the stitches in a measured swatch and this turns any round count into centimetres: how wide a disc comes out, how tall a stack of rounds stands, and how far a size stated on this site moves once your hand is doing the work. It is the same arithmetic the publish gate runs, with your measurement in place of the model's.
How the model runs
Every size on this site with a leading ~ was computed, not measured. The whole model is two constants and four lines of arithmetic, and it is written out here so the figures the tool prints can be checked against it by hand.
| Quantity | On a 4.0 mm hook |
|---|---|
| Stitch widthhook mm × 0.16 | 0.64 cm |
| Round height0.8 × stitch width | 0.51 cm |
| A round worked flat, acrossstitches × width ÷ π | 36 → 7.33 cm |
| The same round worn round somethingstitches × width | 36 → 23.04 cm |
| Rounds stacked, tallrounds × height | 12 → 6.14 cm |
| Laid out in a lineevery stitch in the piece × width | 354 → 226.56 cm |
Four dimensions rather than one, because a coaster quotes what it measures across, a hat quotes what it measures around, a toy quotes how tall it stands and a chain quotes its length. Comparing a stated size against only one of them reads a correct hat as a tenfold error. That is the reason the list is written the way it is in scripts/audit-patterns.py, and the tool above keeps all five rows for the same reason.
This tool measures your gauge, never a pattern's
Not one of the 113 records on this site states a gauge as a number. A stitch density written as a figure is a measurement claim, and nobody here has swatched one — so scripts/check-completeness.py reports a numeric gauge as an unearned claim every time it runs. What the records carry instead is a technique: work tight enough that the stuffing cannot show between the stitches, and a looser hand gives you a larger animal and nothing worse.
The consequence for this page is exact. The right-hand column of the table above is the model, derived from the hook the pattern names; it is labelled as the model wherever it appears and it is not a gauge anybody took. The left-hand column is yours, from the swatch you measured. The gap between them is the number worth having, and it is the reason the two are printed side by side rather than one being quietly used for the other.
2 of the 113 records name a hook in prose rather than in millimetres, so they have no model width at all, and the tool says so on those rather than picking a number for them.
Where this sits in the publish gate
Stage 3 of the gate a pattern passes before it is published is this geometry, and the line every record carries for it reads: geometry-check.py — 113 checked, 0 errors, 4 warnings.
.claude/skills/pattern-quality-gate/geometry-check.py is the file. It asks two questions of a piece a pattern calls flat: does it stop growing, which makes it a wall rather than a disc, and does it grow faster than its opening ring, which makes it ruffle. Neither question needs your gauge — a shape is a shape at any tension. What needs your gauge is every centimetre on this page.
What each check proves, and what none of them can, is set out on how we check.
What a swatch cannot settle
Gauge is one number about one square of fabric. It does not know that stuffing pushes a head wider than its stitch count says, that a hat relaxes on a head, that cotton and acrylic at the same hook give different fabric, or that your tension drifts over an evening. Treat every centimetre here as the arithmetic's answer, not the object's.
The structural half of the question — whether a run of counts lies flat, walls up or ruffles — is not a matter of centimetres at all. That one belongs to the chart generator, which draws a round from its counts and reads its shape. This page owns the dimensions; that one owns the shape, and neither repeats the other.
For how much yarn those stitches will take, and what it costs, the yardage estimator works from the same stitch counts.