The formula
stitches = stitches per unit × width
Your gauge gives stitches per inch (or cm). Multiply by the width you want. Example: 20 stitches over 4 inches is 5 per inch, so 20 inches needs 5 × 20 = 100 stitches.
Rounding to a stitch pattern
Many stitch patterns repeat every m stitches and need a few extra stitches to be symmetrical. The calculator subtracts the extra edge stitches, rounds to the nearest whole number of repeats, then adds the edge stitches back:
cast on = round((exact − edge) ÷ multiple) × multiple + edge
For a 20 inch width at 5 stitches per inch with a multiple of 6 plus 2: (100 − 2) ÷ 6 = 16.3, which rounds to 16 repeats, so 16 × 6 + 2 = 98 stitches. That knits to 98 ÷ 5 = 19.6 inches.
Tips
- Add seam allowance stitches if the piece will be sewn together.
- Cast-on edges can pull in; use a stretchy method for a flat edge.
- Swatch first. A gauge that is off by one stitch per 4 inches changes a 40 inch piece by a few inches.
Frequently asked questions
How many stitches should I cast on for a 20 inch width?
It depends on your gauge. At 5 stitches per inch you need 100 stitches before rounding to a stitch pattern.
What does "multiple of 6 plus 2" mean?
The stitch pattern repeats every 6 stitches and needs 2 extra stitches to finish the row, so valid counts are 8, 14, 20 and so on.
Should I cast on extra stitches for seams?
Yes, if the pattern does not already include them. Add one stitch per seamed edge, or whatever your pattern recommends.
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