This is a graph that can be worked knitted, crocheted or with Afghan stitch. Looks best if done in single crochet if you are crocheting it. I have never knitted or used afghan stitch for these.

It is 150 x 112 stitches. The size of the blanket will depend on your gauge/hook size and yarn. You can add/remove rows to top and bottom to make it bigger/smaller as you feel fit.