Knitting gauge: how to knit and measure a swatch
Gauge is how many stitches and rows fit in 10 cm of your fabric. Every number in a pattern depends on it, so a swatch is not a formality — it is 20 minutes that save weeks of work.
Work out gauge in the calculator →
How to knit the swatch
- Same yarn and needles as the garment. If the garment is knit in the round, swatch in the round too, or knit every row on the right side and carry the yarn across the back.
- Same stitch pattern. Stockinette, rib, cables and colourwork all have different gauges. For a cabled sweater, swatch with a cable.
- At least 15 × 15 cm. Edge stitches are always uneven, so you measure in the middle.
- Wash and dry it exactly as you will the garment: soak, roll in a towel, lay flat. After washing stitches relax — wool often grows by 5–10%.
Worked example: set-in sleeve sweater
This is real output from the builder for size M (bust 92 cm, neck 35.5 cm, upper arm 29 cm, length 60 cm) at a gauge of 22 sts and 30 rows per 10 cm (4 in).
Key numbers
- Body cast-on
- 122
- Sts at bust (per piece)
- 114
- Sts at waist (per piece)
- 94
- Rows to armhole
- 116
- Total rows
- 180
- Armhole: bind off
- 6 + 2
- Armhole: decreases every 2 / 4 rows
- 5 / 2
- Sts across shoulders
- 84
- Neck sts
- 42
- Shoulder sts
- 21
Finished garment
- Bust circumference
- 103.6 cm
- Ease
- +11.6 cm
- Length
- 60 cm
- Waist / hips
- 85.5 / 110.9 cm
- Armhole depth
- 19.5 cm
- Shoulder width
- 9.5 cm
- Shoulder slope
- 2 cm
- Yarn (estimate)
- 1320–1680 m
How to measure
Lay the swatch flat without stretching. Measure 10 cm in the middle with a ruler and count the stitches across, then the rows up. Half stitches count — 21.5 is neither 21 nor 22.
You do not need exactly 10 cm. Measure any length and convert: gauge = stitches ÷ centimetres × 10. For example, 16 sts over 7.5 cm → 16 ÷ 7.5 × 10 = 21.3 sts per 10 cm. The gauge calculator on the site does this for you.
Why half a stitch matters
A 100 cm sweater at 22 sts per 10 cm is 220 stitches. If your swatch is really 21 sts, the same 220 sts make 105 cm; at 23 sts, 96 cm. One stitch per 10 cm is a whole size up or down.
So the builder never rounds your gauge: enter 21.3 and it calculates with 21.3. How gauge turns into sweater stitch counts.
If your gauge does not match the pattern
More stitches than the pattern — you knit tighter: try needles 0.5 mm larger. Fewer stitches — go smaller. Or keep your gauge and convert the pattern to your yarn.
FAQ
Do I really need to wash my swatch?
Yes. Most yarns change size after washing: wool and merino relax, cotton can shrink in length. Without washing you calculate for fabric that will not exist after the first wash.
How big should a gauge swatch be?
At least 15 × 15 cm, 20 × 20 cm for chunky yarn. Measure 10 cm in the centre, away from the edges and the cast-on.
Can I measure gauge on a finished garment?
Yes, if it is the same yarn and stitch pattern and it has been washed. Count in the middle of a piece, not near the seams.
Why is my gauge different in the round?
Many knitters purl tighter or looser than they knit. In the round you only knit, so gauge can differ by 0.5–1 st per 10 cm.