Knowing how to determine the number of outlets for an electrical circuit can be confusing. The National Electrical Code has no requirement on the maximum number of outlets you can put in a residence, because in a house not all outlets will be used at the same. Any motor operated appliance that exceeds 1,200 watts should be placed on a dedicated circuit.
Check the size of the breaker you are installing for your outlets. The National Electrical Code (NEC) requires 20 amp circuits to feed residential 15 amp 120 volt receptacles.
Multiply amps by volts to obtain the total wattage for the circuit. A 20 amp single pole breaker multiplied by 120 volts equals 2,400 watts.
Multiply 2,400 watts by 60 percent (2,400x.60) to obtain the total safe maximum wattage of 1,440. NEC standards require you do not exceed 60 percent of the wattage on a circuit.
Dividing 1,440 watts by 120 volts will show you can safely place 12 residential 15 amp receptacles on that circuit.