All glossary terms
Gauge
Gauge is the number of stitches and rows that fit in a set measurement — usually a 4-inch (10 cm) square — with a given yarn and hook or needle. Matching a pattern's gauge is what makes your finished project come out the right size.
Makers check gauge by working a swatch and measuring it. If you have too many stitches per inch, go up a hook or needle size; too few, go down. Skipping the swatch is the most common reason a sweater or hat ends up the wrong size.