Why gauge decides the size
A pattern's stitch counts assume its gauge. Knit 200 stitches at 4.5 stitches per inch instead of 5 and a 40 in sweater comes out 44.4 in. Small differences add up fast on big pieces.
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Knitting and crochet gauge calculator
Enter your swatch and the pattern's gauge. You'll see how big the piece will really come out, and the cast-on that hits the size you want.
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- Shows the working
Measure gauge over at least 4 in (10 cm), away from the edges, after washing and blocking the swatch the way you'll treat the finished piece.
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Good to know
Two ways to fix it
Change needle or hook size and swatch again (up a size if you have too many stitches per inch, down if too few). Or keep the fabric you like and recalculate: target width × your stitches per inch, rounded to the pattern's stitch multiple.
Row gauge
Row gauge matters when the pattern counts rows for length, raglans or colorwork. When it says "knit until piece measures", it matters less.