In this paper, a quick method for estimating the patch width is presented using CMA. The proposed method can be completed in four steps, based on the relationship between the patch width as the variable and different resonant frequencies, and has been validated using four substrates. This method is advantageous as it facilitates antenna designers in estimating the width of the radiator patch using only CMA without the effects of substrate and excitation. Basically, the generated formula enables the calculation of the actual patch width by simply substituting the width of the patch produced based on one of the CMA’s characteristic angle. This parameter which is originally used to find the natural resonant frequency of the structure makes the proposed method time- and resource-efficient. The set of obtained results have been validated to be realistic with satisfactory accuracy.