Calculate soil for raised garden bed
Use the inside dimensions, not the outside lumber size. That small difference gets expensive on longer beds.
Length (ft) x Width (ft) x Depth (in) / 12 = cubic feet of soil
Example: an 8 x 4 bed filled to 10 inches needs about 26.7 cubic feet of material. At 1.5 cubic feet per bag, that lands at 18 bags.