I usually take length in feet X width X thickness and divide by 12.
You have to determine what widths and lengths are available at supplier first. You can do all the "math"then find out they don't have those width boards. Then everything goes out the window and turns into a fire drill. You're at the lumber yard scrambling your brains, you end up grabbing what "looks like more than enough." Hah!
Another way is to take the total width in your case 30" wide, choose some lumber you like, and lay them side by side till you get say 35" (for waste), then figure how many 50" lengths you can get out of the boards, then repeat so you have 4 panels. Same thing for the sides.
The most efficient way I know of is to use Cutlist, but again, you have to know what widths and lengths are available. Take your laptop with you and enter it into the materials and it will figure it out on the spot. I've never done it but it seems like it would work. I never use it for dimensional lumber, only sheet goods.
What ever you figure, GET 20% MORE. Yes! Because when you get to laying out lumber & grain matching, you'll find out real quick its not just a matter of board feet. Unless grain matching doesn't matter to you.....
The short answer is: there is no math that will work.
You have to determine what widths and lengths are available at supplier first. You can do all the "math"then find out they don't have those width boards. Then everything goes out the window and turns into a fire drill. You're at the lumber yard scrambling your brains, you end up grabbing what "looks like more than enough." Hah!
Another way is to take the total width in your case 30" wide, choose some lumber you like, and lay them side by side till you get say 35" (for waste), then figure how many 50" lengths you can get out of the boards, then repeat so you have 4 panels. Same thing for the sides.
The most efficient way I know of is to use Cutlist, but again, you have to know what widths and lengths are available. Take your laptop with you and enter it into the materials and it will figure it out on the spot. I've never done it but it seems like it would work. I never use it for dimensional lumber, only sheet goods.
What ever you figure, GET 20% MORE. Yes! Because when you get to laying out lumber & grain matching, you'll find out real quick its not just a matter of board feet. Unless grain matching doesn't matter to you.....
