Concrete Ingredients Calculation. For Cement, Sand and Coarse Aggregate. This is a Volumetric Calculation. Assuming we need 2 m3 of concrete for M20 Concrete Mix, (Mix Ratio, M20 = 1 : : 3) Total Part of the Concrete = 1++3 = Parts. Therefore, Cement Quantity = (Cement Part / Concrete Parts ) * Concrete Volume.