This is more a calculator than an actual pattern generator. You need to figure out your tension/gauge, and how many stitches you’ll be casting on, then this works out the rate of decreases for you.

You need some sort of idea as to what you’ll be doing at the bottom edge (ie ribbing, seed/moss, etc)- this does not generate any fancy stuff for you.

Great if you are looking to knit a hat or design a pattern and the math gets a little beyond you (as it does).