How many stitches should I cast on?

When we start a new project we usually do not know how many stitches we have to cast on. Everyone knits different and every yarn is also different. So what we will do is:

1. Start with the yarn and the needles that you are planning on using and cast on 12 or 15 stitches.

2. "Knit one row, Purl (reverse) anotherone." repeat for about 2 inches (aprox 5 cm)

3. Meassure it (the width of this sample)

4 Calculate as follows: