Knitting Cast-On Calculator
Turn your gauge swatch and a target width into the number of stitches to cast on, and rows to knit for a given length.
How it works
Stitches/inch = gauge ÷ 4 · Cast-on = round(stitches/inch × width, to repeat) · Rows = round(row gauge ÷ 4 × length)
Gauge is measured over a 4-inch swatch, so dividing by four gives stitches and rows per inch. Multiplying stitches-per-inch by the width you want yields the cast-on count, and rows-per-inch times the length gives the number of rows to work. Rounding the cast-on to your stitch-pattern repeat — 4 for a 2×2 rib, for example — keeps the pattern aligned all the way across.
Worked example
With a gauge of 20 sts and 28 rows over 4": stitches/inch = 5, rows/inch = 7. A 20" wide, 24" long panel needs 5 × 20 = 100 stitches and 7 × 24 = 168 rows.
Frequently asked questions
Why does gauge matter so much?
Everything scales from it. A gauge that is off by even half a stitch per inch throws a garment out by inches across its width, so always knit and measure a swatch in your actual yarn and needles before casting on.
Why round to a multiple?
Stitch patterns repeat over a fixed number of stitches — a 2×2 rib needs multiples of 4. Rounding the cast-on to that repeat keeps the pattern from breaking at the edges.
Does this account for edge or seam stitches?
No — it gives the stitches for the finished width. Add a stitch or two each side for selvedges or seaming if your pattern calls for them.
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This calculator is for educational purposes. Double-check important results before acting on them.