Swatch and Cast-On Calculator for Knitting (needles or loom)
Swatching for Gauge. Three words we don’t like to hear.
For the Cast-On Calculations:
Swatch is S stitches and measures W wide. The stitches per inch is S/W and desired width is dW. The Stitches to Cast-On = (dW x S/W).Divide Stitches counted in swatch by swatch Width measured. Multiply by Desired Width.
Divide Rows counted in swatch by swatch Length measured. Multiply by Desired Length.