Standard Machine = 4.5 mm Mid-Gauge Machine = 6.5 mm or 7 mm Bulky Machine = 9 mm
The Formula: Multiply the number of stitches in the pattern by the gauge of the machine for the pattern. Divide that result by the gauge of your machine to determine the number of stitches to cast on.
Example Mid-Gauge to Bulky: You have 100 stitches to cast on for the pattern. Multiply times 7 (gauge of machine for original pattern – this example is 7mm) = 700 ÷ 9 (gauge of machine going to use – for this example it’s 9mm) = 77.78 is the number of stitches to cast on to the bulky. In the case of fractions, round up or down depending upon the pattern and stitch pattern repeat.
This same formula is used to calculate rows.
Example: Mid-Gauge to Bulky: You have 168 rows to knit in the pattern. Multiply times 7 (gauge of machine for original pattern – this example is 7mm) = 1176 ÷ 9 (gauge of machine going to use – for this example it’s 9mm) = 130.67 rows to knit on the Bulky.
The same formula must be used to make the calculations for a gauge swatch to determine the stitch and rows to match the pattern gauge.
Example conversion calculation for a swatch:
5 stitches & 6 rows = 1” Gauge of swatch knit on a bulky 9mm – converting to a mid-gauge 7 mm machine
5 stitches x 9 = 45 ÷ 7 = 6.43 stitches per inch
6 rows x 9 = 54 ÷ 7 = 7.71 rows per inch