Making countertops totaling 2.344 Cubic Ft - how many Lbs/bags of WPC+ fine white sand + med aggravate needed for a 1:3 &/or 1:2 ratio?

Assuming the proportions you provided are by volume and the amount of sand and medium aggregate are in equal parts. For a 1 part Lehigh White Portland cement, 1.5 parts fine white sand, and 1.5 parts of medium aggregate by volume, it would be one 94 lb bag of Lehigh White Portland cement, 120 pounds of fine white sand, and 150 pounds of medium aggregate that will yield approximately 2.7 cubic feet of concrete. Yields will vary based upon waste, water content, etc. If you prefer a pre-blended product that only requires the addition of clean water, QUIKRETE® Countertop Mix (No. 110680 - Gray or No. 110681 - Tint-Base) is the product we would recommend using for a concrete countertop as it is a flowable, high strength commercial grade product designed specifically for use in forming concrete countertops. Note that the tint-base is not a pure white. For a decorative appearance, up to 20 pounds of glass or colored stone may be added to one 80 pound bag of QUIKRETE® Countertop Mix. An 80 lb bag of QUIKRETE® Countertop Mix yields 0.6 cubic feet when placed. 2.344 cubic feet of concrete countertop will require 4 bags (of 80 lb each) of QUIKRETE® Countertop Mix. Yields will vary based upon waste, water content, etc. A minimum skill level of intermediate is required for a basic concrete countertop (i.e. simple rectangular shape, no sink cut outs, etc.) while an advanced skill level is required if any added detailing is included in the design.