A method and system for generating a clock distribution circuit for each macro circuit in an ASIC design are disclosed herein. In some embodiments, a method for generating a clock distribution circuit receives the ASIC design specified in a hardware description language (HDL), places each macro circuit in allocated locations on a semiconductor substrate, generates a custom clock skew information for each macro circuit based on a macro clock delay model, generates a clock distribution circuit for each macro circuit placed on the semiconductor substrate based on the generated custom clock skew information, modifies the clock distribution circuit if the generated clock distribution circuit does not meet timing requirements of the ASIC design, and outputs a physical layout of the ASIC design for manufacturing under a semiconductor fabrication process.