Systems and techniques are described for discretizing gate sizes during numerical synthesis. Some embodiments can receive an optimal input capacitance value for an input of an optimizable cell, wherein the input capacitance value is determined by a numerical solver that is optimizing the circuit design. Note that the circuit design may be optimized for different objective functions, e.g., best delay, minimal area under delay constraints, etc. Next, the embodiments can identify an initial library cell in a technology library whose input capacitance value is closest to the optimal input capacitance value. The embodiments can then use the initial library cell to attempt to identify a better (in terms of the objective function that is being optimized) library cell in the technology library. The delay computations used during this process are also minimized.