Hello,
First I'll assume you mean 750 watts, not 750 KW. At 120 volts, 750 watts draws 6.25 amps. A 15 amp breaker with 14 gauge wire would be acceptable or a 20 amp breaker with 12 guage wire. Don't worry about trying to size the breaker to the exact load, just don't overload a circuit. BTW, if you did mean 750KW, you'll need to find a 6250 amp breaker and that's going to cost you [Linked Image]