Gauge Swatch Guide
A gauge swatch is a 4-inch square of fabric knit in the project stitch with the project yarn and needles. It is the only reliable way to know whether the finished garment will fit. Swatching takes 30 minutes and saves entire projects from disaster.
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Method
Cast on enough stitches to make a swatch at least 6 inches wide (you measure the central 4 inches and ignore the edges). Knit in the project stitch (usually stockinette unless the pattern calls for cables, lace, or another stitch). After 6 inches, bind off.
Wet-block before measuring
Soak the swatch in lukewarm water for 20 minutes, squeeze out excess water, and pin flat to dry. Wet-blocking changes most fabrics by 5–15%; measuring an unblocked swatch gives the wrong gauge.
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Measuring
With a hard ruler, count stitches across 4 inches in the centre of the swatch. Count rows over 4 inches the same way. Compare with the pattern's stated gauge.
Adjusting
If you have too many stitches per 4 inches, try a needle one size larger. Too few, try one size smaller. Re-swatch and re-block. The needle that gets the gauge right is the needle to use for the project, regardless of what the pattern recommends.
Abbreviation reference
| Abbreviation | Meaning |
|---|---|
| CO | cast on |
| BO | bind off |
Tips
- Always wet-block the swatch before measuring — gauge changes by 5–15% with blocking.
- Measure the central 4 inches and ignore the edges.
- A swatch that is too small to measure 4 inches across is unreliable; cast on more stitches and try again.
In depth
The gauge swatch is the most-skipped and most-important step in any garment project. The 30 minutes of swatching prevents the garment from coming out two sizes too big or too small — which is the most common cause of unsuccessful projects.