An analytical model is proposed for computing the resonant frequency, quality factors, bandwidth, input impedance, and gain of electromagnetically coupled stacked equilateral triangular patch antennas. The model is simple, fast, and suitable to apply directly in the computer-aided design (CAD) programs. The accuracy of the present model is computed against our newly performed and previously reported experimental results for various sets of relative permittivity and thickness of microstrip structure. We have also employed commercial software to validate the model.