Gauge is the number of stitches and rows in 10cm (4”). It looks like a small number, but for garments and hats — anything where size matters — it is the single most important factor that determines the finished dimensions.
Why it matters
If the pattern gauge is 20 stitches per 10cm but yours is 18, the same 100 stitches will come out about 55.6cm wide instead of 50cm. Small differences accumulate across the full width and length, so skipping the swatch can leave you with a finished piece that doesn’t fit.
How to do it right
Knit the swatch larger than the 10cm you’ll measure — usually 15cm or more. Use the same yarn, needles, and stitch pattern as the project, then wash or block it the same way you’ll treat the finished piece before measuring the center 10cm. Leave the edges out of the measurement; they curl and their tension differs.
What beginners often miss
Knitting the swatch too small, or only recording pre-wash numbers, can make it differ from the finished piece. Wool, cotton, and alpaca in particular can change in length and width after washing and drying, so always measure in the final state.
The gauge adjustment formula
To adjust the stitch count, multiply the pattern’s stitch count by your gauge and divide by the pattern gauge. Row counts adjust the same way.
Formula: adjusted stitches = pattern stitches x your stitches per 10cm / pattern stitches per 10cm. For example, with a pattern gauge of 20, your gauge of 18, and a cast-on of 100, you’d cast on 90.
| Situation | Meaning | Adjustment |
|---|---|---|
| You have more stitches | You knit more tightly | Go up a needle size, or recalculate with more stitches |
| You have fewer stitches | You knit more loosely | Go down a needle size, or recalculate with fewer stitches |
| Only rows differ | Vertical length changes | Adjust rows at armholes, sleeves, and body length |
Common measuring mistakes
Measuring all the way to the swatch edges can give you too few or too many stitches. Always measure the center 10cm, and record awkward numbers like 4.5 stitches as-is instead of rounding.
If the yarn grows after washing, base your math on the post-drying numbers, not the pre-wash ones. The key is to put the swatch through exactly what the finished piece will experience.
Pre-project checklist
- Knit a swatch 15cm or larger
- Use the same stitch pattern as the project
- Measure after washing or blocking
- Record stitches in the center 10cm
- Record rows too
FAQ
My gauge is tighter than the pattern — what now?
Go up a needle size and swatch again. If it still doesn’t match, adjust with the stitch-count formula.
Is matching stitch gauge enough?
For garments, row gauge matters too. It affects vertical measurements like armholes, sleeve caps, and body length.
Do small accessories need a swatch?
Hats, gloves, and socks that need exact sizing do. Dishcloths and decorative pieces can skip it.