NEC load calculator
Estimate your home’s total electrical demand and the service size it needs, using the NEC 220.82 optional method. Enter your home details and major loads to see your demand in amps and a recommended panel size.
How it works
- Calculates general lighting load from floor area plus standard circuits.
- Adds major appliance and HVAC loads with NEC demand factors.
- Returns total demand in amps and a recommended standard service size.
What changes your result
- Conditioned floor area
- Major appliances and their nameplate ratings
- HVAC — heating kW or air-conditioning tonnage
- New electrified loads such as an EV charger, heat pump or induction range
Frequently asked questions
How do I calculate my home’s electrical load?
Add the general lighting load (about 3 VA per square foot) plus required circuits to the nameplate ratings of major appliances, then apply NEC demand factors. This calculator does it with the 220.82 optional method and recommends a service size.
What size electrical service does my house need?
Most modern homes use 150–200 amp service; smaller or older homes may have 100. The right size depends on your square footage and major loads. This calculator estimates demand and the standard service that fits with margin.
Do I need a bigger panel to go all-electric?
Sometimes, but not always. Adding an EV charger, heat pump and induction range raises demand, yet many panels still have headroom and load management can defer upgrades. Run your numbers before assuming you need an upgrade.