Reference / Techniques
Gauge
Gauge is stitches-per-inch, and it is why two people following one pattern get different sizes. Hook size, yarn weight, and personal tension all move it.
When it matters
- Garments and anything that must FIT: check gauge first, always. Work the pattern's gauge swatch (usually 4 by 4 inches), measure, and change hook size until your numbers match the pattern's.
- Amigurumi: exact size rarely matters, but DENSITY does. Fabric loose enough to show stuffing through the stitches wants a smaller hook. Most amigurumi is worked a size or two below the yarn band's suggestion.
The one ratio worth memorizing
A single crochet stitch is nearly square: about 0.9 times as tall as it is wide. That ratio is why six increases per round lies flat, and why the same recipe in a taller stitch would ruffle.