how to i calculate how much yarn i need

[pita1213]

i finially finished the middle panel for an afghan i'm making for my fil. the orignial pattern called for making 9 panels 5 of which had teh different symbols for each military branch and then teh other four had yellow ribbons and said pray for out troops. instead i just did the army logo for the middle panel and want to do the other 8 panels in the red heart camo yarn. but i haben't go any idea how much yarn i will need for each panel. the panels ar 70 stiches wide and 92 rows long. i get rows per inch and 4 stitches per inch if i measured and counted right. how do i figure out the quanity of yarn i need or does someone know of a website to input the info and it tell me the amount?

thanks for any help.

[pita1213]

forgot to add i'm crocheting this
and the pattern isn't very helpful as i found the amounts it recommended for each color were off quite a bit.

[YankeeMom]

How many rows & stitches per inch do you get with the yarn? I only see 4 stitches per inch. I'd need how many rows per inch too.

The blanket is 70 stitches wide, and 92 rows long.
How big is the yarn, how many yards per skein?

[pita1213]

soory thought i put that it was 4 rows per inch.
it's red heart worseted 4 medium. 255 yards/skein