This calculator is for existing electrical panels. This calculation is based on the National Electric Code (NEC) Article 220.83 and will help determine what the electrical load will look like after installing a heat pump water heater (and other electrical equipment that may be installed, such as solar PV, electrical vehicle chargers, or a heat pump).
* denotes required fields. This tool provides estimates and does not replace an evaluation conducted by a licensed electrician.
Select all electrical appliances and power losses below. If known, enter the exact wattage of the appliance. Look for the nameplate rating of large appliances. If the value cannot be determined, leave the field blank and a default value will be used.