Knitting Gauge Calculator
Turn your swatch gauge into the exact stitches to cast on and rows to knit for any finished size, and see your stitches and rows per inch. Calculates in your browser.
Cast on
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Show the math
cast-on = width × (stitch gauge ÷ 4) · rows = length × (row gauge ÷ 4)
Gauge is given per 4 inches (10 cm), so dividing by 4 gives the per-inch rate. Multiply by your finished measurement and round to whole stitches and rows.
Always swatch in the same stitch pattern, needles, and yarn you will use, and block it first, gauge changes after washing. A half-stitch per inch off can mean a garment that is inches too big or small.
What this does
A knitting gauge calculator turns your swatch gauge into the exact stitches to cast on and rows to knit for any finished size.
How to use it
- Knit and measure a swatch.
- Enter stitches and rows over 4 inches.
- Enter your finished width and length.
- Read the cast-on count and total rows.
How it works
Gauge is given over 4 inches, so dividing by 4 gives stitches and rows per inch. Block your swatch first — gauge often changes after blocking.
cast-on = stitches per inch × finished width
Understanding your result
The cast-on count is only as good as your swatch, so block the swatch the way you will block the finished piece before measuring, because gauge often shifts after washing. If your numbers come out a touch off, change needle size rather than fighting your natural tension, and trust the stitch count over the listed needle on the ball band.
Example
At 5 stitches per inch, a 20-inch width needs 100 stitches cast on.
Sources & methodology
Last updated .
Frequently asked questions
How is cast-on found?
Gauge is given over 4 inches, so dividing by 4 gives stitches and rows per inch. Multiplying by your finished width and length gives the cast-on count and total rows, rounded to whole numbers.
Why does gauge matter so much?
A small error per inch multiplies across a whole garment, half a stitch per inch over 40 inches is 20 stitches, inches of difference. Always swatch first.
Should I block my swatch?
Yes. Wash and block the swatch the way you will treat the finished piece, because gauge often changes after blocking.
Is anything saved?
No, all calculations run locally in your browser.
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