Cast On Calculator — Stitches for Any Width

Multiply your desired width in cm by your stitches per cm (your gauge divided by the size of the swatch you measured it over, normally 10cm). Then adjust for pattern repeats by rounding to the nearest multiple of your repeat count, and add edge stitches if knitting flat.

Edge stitches (selvedge stitches) are extra stitches at each side that create a neat edge or are used in seaming. Typically 1-2 stitches per side. When knitting in the round, you do not need edge stitches.

If your stitch pattern repeats over a set number of stitches (e.g. a 4-stitch rib or 8-stitch cable), your cast-on count must be a multiple of that repeat plus any edge stitches. This calculator rounds to the nearest repeat automatically.

When knitting in the round, you do not need selvedge/edge stitches since there are no side seams. Your cast-on count should be a multiple of your pattern repeat without extra edge stitches.

Rounding goes to the nearest multiple, so it can round down. On a narrow piece the rounding step can take the whole body with it: 5cm at a gauge of 8 stitches per 10cm is only 4 stitches, and rounding that to the nearest 12 leaves nothing. Rather than print a cast-on of zero, the calculator refuses and names the values to change. Widen the piece, use a finer gauge, lower the Pattern Repeat, or lower the Round to Nearest value in Advanced Options.

The pattern body is the cast-on count minus the edge stitches, so a body below zero would mean the edge stitches alone come to more than the whole cast-on. On a narrow piece at a heavy gauge that can happen: 6.5cm at a gauge of 8 stitches per 10cm is 5 stitches in all, so with no pattern repeat 6 edge stitches leave a body of minus 1. Rather than print a negative pattern body, the calculator refuses and names the field to change. Lower Edge Stitches, or increase Target Width or Stitch Gauge. A body of exactly zero is a different case and is answered rather than refused: the whole cast-on is selvedge, and the Actual width figure tells you what that comes to.

Stitches are whole, so the raw count is rounded to a whole number, and the pattern repeat and the Round to Nearest value round it again to the nearest common multiple. Rounding to the nearest multiple can land either side of your target, so the finished piece may come out slightly narrower or slightly wider. The Actual width figure tells you which way it went, and it is measured at the gauge you entered rather than after blocking.