Mold sizes for an 18 inch high bench with 8 inch by 15 inch end tables using 3" x 8" lumber for the bench top.

Bottom - 16.5"x 13.5"

Front - 16.5" x 15.5" (Do 16.5" x 15.25" if you want to ensure the bench top is level)

Back - 16.5" x 18"

Sides - 12" x 18" (cut a 4" high x 2.5-2.75" deep space  on one top corner for the wood)

Vertical divider - 15"x ~4" tall. (make sure the bottom edge is coated with melamine)

Horizontal divider - 15" x 5"

ItemCost Per ItemAmount NeededTotal CostWhere to Buy
Melamine Coated Board 3/4 inch$4.001 large board$25.00Home Depot
High Stregnth Concrete Mix$4.00 four 80lb bags$16.00Home Depot
#8 1.5 inch Particle Board Board Screws$8.501 box (25-50 screws)$8.50
Silicon Caulk$7.001 tube$7.00
Teak Oil$19.501 quart$19.50
Circular Saw$50.001$50
Redwood Boards$55.00 two 3 x 8 x 72 (actual dimension are 2.5" x 7.5" by 72") $110Lumber Yard