Various methods and systems are provided for correcting transmit attenuation of an amplifier of a transmit radio frequency (RF) coil for use in a magnetic resonance imaging (MRI) system. In one example, a method includes setting a reference value of transmit attenuation for an amplifier of a transmit radio frequency (RF) coil, acquiring a three-dimensional B1 field map with the transmit attenuation set at the reference value, determining a plurality of mean flip angles for a plurality of slice locations in a pre-scan imaging volume from the B1 field map, determining a transmit attenuation correction value for each of the slice locations based on a prescribed flip angle and the mean flip angle determined for the respective slice location, correcting the reference value of transmit attenuation with the transmit attenuation correction value at each of the slice locations to obtain a final value of transmit attenuation for each of the slice locations, and performing an MRI scan with the transmit attenuation set at the value.