Prior to a hydraulic fracturing treatment, the requisite median diameter of a proppant, dprop, into a fracture of defined length, DPST, may be estimated in accordance with Equation (I): (dprop)2=(A)×(1/qi)×(DPST)B×(1/CTRANS)×(1/ΔSGPS)×(μfluid)  (I) wherein: A is the multiplier and B is the exponent from the Power Law equation of velocity of the transport slurry vs. distance for the fracture geometry; qi is the injection rate per foot of injection height, bpm/ft; CTRANS is the transport coefficient; ΔSGPS is SGprop−SGfluid, SGprop being the specific gravity of the proppant and SGfluid being the specific gravity of the transport fluid; and μfluid is the apparent viscosity of the transport fluid, in cP.