Methods for determining antenna factors of antennas used for radiated emission measurements in electromagnetic interference (EMI) control from 9 kHz to 40 GHz are provided. Antennas included are linearly polarized antennas such as loops, rods (monopoles), tuned dipoles, biconical dipoles, log-periodic dipole arrays, biconical and log-periodic dipole array hybrids, broadband horns, etc., that are used in measurements prescribed by ANSI C63.4 and ANSI C63.10. The antenna calibration methods include standard site method (i.e., three-antenna method), reference antenna method, equivalent capacitance substitution method, standard transmit loop method, standard antenna method, and standard field method.