Baby blanket patterns are easy to find online, for free. You're basically knitting a gigantic square. And you can design your own pattern , with no problem:
Knit a swatch, and write down your stitches per inch and rows per inch gauge
Decide how big you want the blanket to be, in inches
Do some math to decide how many stitches need to go across, and how many rows to knit.
So... let's pretend my stitches per inch is 7 and my rows per inch is 10.
I want my blanket to be 36 square inches
I would have to cast on 7stitchesx36inches: 252 stitches
I would have to knit 10inchesx36rows: 360 rows
At this point, I personally would go "Holy cow I need to find thicker yarn!!!!!"
*disclaimer: I'm sure there's an easier way to do the following*
Anyway, to guesstimate how much yarn you'd need, figure how how many inches of yarn take up 7 stitches... cast on 7 (or 8 to be safe) stitches, then take it off the needles and measure how much yarn you used. Then look at the yarn lable and figure out how much you can knit with one ball. I *always* round up when i do this, because I might not be able to find the same dye lot if I have to buy more.
So... let's pretend I decided that 252 stitches and 360 rows wasn't too much to knit
and I didn't change yarns.... So I cast on 8 stitches, pull them off, and measure my yarn... it took me 10 inches of yarn to knit my 8 stitches... I round that up to 12 inches, becasue 12 fits nicely into yardage measurements and becasue I'm over cautions (and becasue this post is longer than i thought it would be) Looking at the label, I see that each ball is 50 yards, or 150 feet of yarn. How many stitches can do with 150 feet of yarn? If 1 foot gives me 8 stitches, then I can knit 1200 stitches with this ball.
To make the whole thing, I'd need 252 stitches times 360 rows, so that comes to 90720 stitches
in order to knit that many stitches, I'd need 90720 stitches / 8 stitches per inch = 11340 feet of yarn
, OR (11340 feet / 3 feet per yard) 3780 yards of yarn
, OR (3780 yards / 50 yards per ball) 75 and a half balls of yarn
I would DEFINITLY find thicker yarn.
Since I just realized I totally ignored the stitch/row/yardage measurements you gave for the Be Mine yarn, it looks like that would be MORE stitches, since there are more stitches and rows per inch than my made up calculations. Assuming you wanted a 3x3 foot blanket like my made up blanket (is that standar-ish size for blankets for babies???) and your stitches per inch of yarn is the same ...
If I can knit 90720 stitches on 75 balls...
You would need
**okay, I have to go baby sit before I can figure out this math. I will come finish later, if anyone is interested (just call me OCD with math)***