# Crochet pattern resizer

> Make an amigurumi pattern bigger or smaller by rebuilding it on a wider base — every round rewritten exactly, and a straight answer when a pattern cannot be scaled.

**How resizing actually works.** The usual answer to "how do I make this bigger" is "use thicker yarn", which is true, limited, and not what was asked. The other real answer is to rebuild the piece on a wider base: a shape started with six stitches in a magic ring and grown six a round can be started with eight and grown eight a round. Every proportion is preserved and the piece comes out 8/6 as wide.

**Why that is exact rather than approximate.** In this construction every round is either the base repeated — `6x (…)` — or a plain run of stitches whose length is a multiple of the base. Changing the base to B rewrites the first kind as `Bx (…)`, leaving the stitches inside the brackets untouched, and the second as `k × B / b`, which is a whole number precisely because k was a multiple of b. No rounding, no drift, no round that "nearly" works. The number of rounds does not change; the piece gets wider and taller together.

## The bases it offers

| Base | Scale from a 6-stitch start | Effect |
| --- | --- | --- |
| 5 | 0.83× | narrower and shorter |
| 6 | 1.00× | the pattern as written |
| 7 | 1.17× | wider and taller |
| 8 | 1.33× | wider and taller |
| 9 | 1.50× | wider and taller |
| 10 | 1.67× | wider and taller |
| 12 | 2.00× | wider and taller |

Below five the magic ring stops closing tidily; far above twelve the first rounds ruffle.

## A worked example

A three-increase-round ball — the sphere calculator's own output — rebuilt on a base of 8. Its widest round goes from 18 stitches to 24, a linear scale of 1.33×:

```
Pattern name: "Ball"
start: magic ring

// generated by the crochet sphere calculator — edit freely
Round 1: 8 sc in ring → 8
Round 2: inc x8 → 16
Round 3: (sc, inc) x8 → 24
Round 4-6: 24 sc → 24
Round 7: (sc, dec) x8 → 16
Round 8: dec x8 → 8
fasten off
```

## When it refuses, and why that is the useful part

A hand-tuned round — colourwork spelled stitch by stitch, an ear built mid-round, a bobble placed at stitch 14 — has no repeat to scale and no divisor to scale by. There is no honest way to widen `8 sc, 2 sc[#fff], 3 sc, inc`: those stitches are placed against a picture, not against a count. So the tool finds the first line it cannot scale, names it and stops, because emitting a pattern whose rounds no longer add up would be worse than refusing — and "round 5 places colours stitch by stitch" is itself the answer to why resizing that pattern is a re-charting job.

The tool is at [https://crochet3d.com/tools/crochet-pattern-resizer](https://crochet3d.com/tools/crochet-pattern-resizer), with six questions answered.

Source: https://crochet3d.com/tools/crochet-pattern-resizer