An approach provides for predictive and continuous supply voltage adjustment of a Radio Frequency (RF) power amplifier in a wireless terminal. A voltage value is predictively determined to continuously control a voltage converter of the wireless terminal for maximizing RF power amplifier efficiency. A control signal is output based on the determined voltage value, wherein, in response to the control signal, the voltage converter outputs a power amplifier supply voltage of the wireless terminal. The above arrangement has particular application to a cellular handset for improved battery life.