HOW TO USE THE BLANKET SIZE CALCULATOR 
​(Not suitable for C2C blankets)
Make a sample of ten stitches across from your desired stitch (usually sc/hdc/dc) and do two rows. Measure this sample across and down in inches. It's okay to include any height of the original chain.
Put the width in inches in the question marked 1. Put the height in inches in the question marked 2.
On your graph, count how many blocks across and down it is. Put the number of blocks from the width in question 3, and the number of blocks from the height in question 4.
On the right hand side, it will show how wide and tall your blanket should end up being.