A 1600 watt hairdryer will draw approximately 13.3 amps when plugged into a 120 volt outlet. The current draw is determined by the formula I=P/E, where I is the current in amps, P is the power in watts, and E is the voltage in volts. Therefore, a 1600 watt hairdryer plugged into a 120 volt outlet will draw approximately 13.3 amps of current.