Quick answer: Knit a 6-inch square in your pattern stitch, wash and block it the same way as the finished project, then measure stitches and rows per 4 inches in the centre of the swatch.
Why swatch at all
Your gauge determines the size of your finished project. Off by half a stitch per inch and a sweater can come out 2-3 inches too big or too small. Swatching takes 30 minutes and saves hours of ripping back.
How to knit a good swatch
- Cast on 30-40 stitches in your project yarn and needles.
- Work in your pattern stitch (stockinette, ribbing, cables — whatever the pattern uses).
- Knit until the swatch is at least 6 inches tall.
- Bind off loosely.
- Wash and block the swatch exactly as you'll wash the finished project. This step is non-negotiable.
- Let the swatch dry completely before measuring.
How to measure
- In the centre of the swatch (not the edges), lay a ruler horizontally.
- Count stitches across 4 inches and rows over 4 inches.
- If too many stitches: go up a needle size. Too few: go down.
Common mistakes
- Not washing the swatch before measuring
- Measuring at the edges where tension is tightest
- Assuming gauge matches the ball label — everyone knits differently