How to knit and measure a gauge swatch
- Knit a swatch bigger than 4 in (10 cm). Use the same yarn, needles and stitch pattern as your project. Many knitters aim for about 6 in (15 cm) square so they can measure away from the edges.
- Block it the way you’ll block the finished piece. If you’ll wash the project and dry it flat, do the same to the swatch, and let it dry completely before you measure.
- Measure in the center. Lay the swatch flat without stretching it, and measure across the middle, away from the edges, where the stitches are most even.
- Count partial stitches. Half a stitch over 4 in makes a real difference, so count to the nearest half stitch. You can also measure over a wider area and let the swatch calculator above do the math.
- Count rows the same way, measuring vertically.
Why gauge matters
Gauge sets the size of everything you knit. In the example above, the pattern is written for 20 stitches per 4 in and casts on 100 stitches for a piece 20 in wide. At 18 stitches per 4 in, those same 100 stitches come out about 22.2 in wide, roughly 11% bigger. On a sweater with a front and a back like that, the body would be more than 4 in bigger around than intended. Gauge also changes how the fabric feels and drapes, and how much yarn the project uses.
How the math works
- Stitches at your gauge = pattern stitches × your gauge ÷ pattern gauge. Example: 100 × 18 ÷ 20 = 90 stitches.
- Width of any stitch count = stitches ÷ gauge × 4 in (or × 10 cm). Example: 90 ÷ 18 × 4 = 20 in.
- Gauge from a swatch = stitches counted ÷ width measured × 4 in (or × 10 cm). Example: 19 ÷ 4.25 × 4 ≈ 17.88 stitches per 4 in.
- Stitches for a target width = width ÷ 4 in (or ÷ 10 cm) × your gauge. Example: 20 ÷ 4 × 18 = 90 stitches.
- Rows work the same way with row gauge and length, rounded to the nearest whole row.
When a stitch count has to fit a stitch repeat, the calculator rounds to the nearest valid count below and above the exact result.
Stitch multiples explained
Many stitch patterns repeat over a fixed number of stitches, and patterns state this as a multiple. “Multiple of 4 + 2” means any count you get by adding 2 to a multiple of 4: 6, 10, 14 … 90, 94, 98, and so on. The extra stitches usually balance the pattern at the edges. For example, k2, p2 ribbing worked flat over a multiple of 4 + 2 starts and ends with k2.
If the converted count doesn’t land on one of those numbers, the pattern won’t line up across the row. That’s why the calculator shows the nearest valid count below and above the exact result, with the width each one gives, so you can choose the one closest to the size you want. For plain stockinette or garter stitch, leave the multiple at 1 and the extra at 0.
Adjust your needles or adjust the pattern?
If you get more stitches per 4 in than the pattern, your stitches are smaller than the designer’s, so try larger needles. If you get fewer stitches, they’re larger, so try smaller needles. Knit a new swatch after each change.
Changing needles is usually the simplest fix when you’re close to gauge and like the fabric either way. If the fabric you like best is at a different gauge, or your yarn knits up differently from the one the pattern calls for, keep your gauge and convert the pattern with the calculator instead. Convert every stitch count that affects size, not just the cast-on (sleeves, necklines and other sections too), and spread any shaping over the converted number of rows.
Frequently asked questions
What’s the difference between stitch gauge and row gauge?
Stitch gauge is how many stitches fit across a set width, and it controls how wide a piece is. Row gauge is how many rows fit in a set height, and it controls length. Patterns usually stress stitch gauge, because many pieces are worked to a measured length (“work until piece measures 14 in”), which takes care of length on its own.
Does blocking change gauge?
It can. Many yarns relax or bloom when they’re washed and dried, so a swatch may measure differently before and after blocking. Measure your swatch after blocking it the same way you’ll block the finished project.
Can I use this calculator for crochet?
Yes. The math is the same for crochet: count stitches and rows (or rounds) over 4 in or 10 cm, and enter the pattern’s stitch repeat as the multiple if it has one.
What if my stitch gauge matches but my row gauge doesn’t?
That’s common. Where the pattern gives lengths as measurements, follow the measurement and you can ignore row counts. Where it counts rows, such as shaping intervals, charts or a set number of rows, enter the row count in the converter to scale it to your row gauge, and spread any increases or decreases over the new number of rows.
Should I use inches or centimeters?
Use whatever your pattern uses. Gauge over 4 in and gauge over 10 cm differ by less than 2% (4 in is 10.16 cm), so patterns treat them as the same, and so does this calculator. Switching units here converts the measurements you entered but leaves gauge numbers unchanged.
About this calculator
This free knitting gauge calculator does the arithmetic knitters usually do on paper, plus two things that are easy to miss: it keeps stitch patterns intact by rounding to the pattern’s stitch multiple, and it shows the actual width each option gives so you can choose. Results are only as accurate as your swatch measurement, so knit and measure a swatch first.