Knitting Gauge: Stitches per Inch, Cast-On Count, and Fixing a Mismatch
October 29, 2026
Gauge is the number of stitches and rows per inch (or per 10 cm) in your knitting with a given yarn and needles. It determines the size of the finished piece. Knit a swatch at least 4 to 6 inches square, wash and dry it as you would the finished item, then measure stitches and rows over 4 inches and divide by 4.
Suppose your gauge is 5 stitches and 7 rows per inch. For a sweater with a chest of 40 inches plus 2 inches of ease (a loose fit), the circumference is 42 inches. Stitches around = 42 × 5 = 210 stitches (105 each for front and back). A body length of 24 inches needs 24 × 7 = 168 rows.
Skip the math and get your answer instantly:
Open the Percentage Calculator →Effect of Gauge Mismatch
A pattern calls for 5.5 stitches per inch and asks you to cast on 110 stitches for a 20-inch piece. Your gauge is 5.0 stitches per inch. At your gauge, 110 stitches measure 110 ÷ 5 = 22 inches, 10% wider than intended. A difference of only half a stitch per inch changes the size by one clothing size or more. Over a 40-inch garment, a 10% error adds 4 inches. If you are tighter (6 stitches per inch), the same 110 stitches yield 18.3 inches, too small.
| Your gauge (st/in) | Width of 110 stitches | Difference from the 20-inch target |
|---|---|---|
| 5.0 | 22.0 in | +10% |
| 5.5 (pattern) | 20.0 in | 0% |
| 6.0 | 18.3 in | -8% |
Fixing a Mismatch
If you have too few stitches per inch (loose), try a smaller needle; if too many (tight), go up a needle size. Make another swatch until it matches. Alternatively, recalculate the stitch counts for your gauge: stitches needed = target inches × your gauge. For a 20-inch piece at 5.0 stitches per inch: 100 stitches; but then pattern shaping instructions such as decreases every certain number of rows need to be recalculated. Row gauge matters for length: if you have fewer rows per inch, you need fewer rows.
Practical Planning
Round stitch counts to the multiple required by the stitch pattern (for example, a multiple of 4 plus 2 for a rib). Include a few extra stitches for seams. Ease depends on the garment: 0 to 2 inches for fitted, 2 to 4 for classic, 4 or more for oversized. Block the swatch the same way as the piece, since wool relaxes after washing and cotton may grow.
Yarn Estimates
A rough rule is that an adult sweater needs 1,000 to 1,600 yards of worsted-weight yarn, depending on size. Check the pattern and buy a little extra from the same dye lot. Measuring gauge is the cheapest way to avoid a garment that doesn't fit.
Frequently Asked Questions
How do I measure gauge?
Knit and wash a swatch, then count stitches and rows over 4 inches and divide by 4.
How many stitches to cast on?
Target circumference in inches times stitches per inch.
What happens if my gauge is off?
The garment will be larger or smaller than intended.
How do I change my gauge?
Change the needle size.
Why wash the swatch?
Because yarn can change size after washing.