Calculate residential electrical load per NEC 220.83. Check if a home's panel can handle the demand. Learn more
Calculate residential electrical load per NEC 220.83. Check if a home's panel can handle the demand.
Property
Standard circuits
Kitchen and laundry
HVAC
NEC only counts the larger of heating or cooling — not both.
Other loads
Your load calculation will appear here, please add:
Amps don't lie. When it's time to upgrade, Workiz helps you book it, build it, and bill it — all in one place.
An electrical load calculation tells you how much power a home actually draws — and whether the existing panel and service can handle it. This matters when a homeowner wants to add a heat pump, EV charger, hot tub, or workshop. If the load exceeds the panel rating, you are looking at a service upgrade.
This tool follows NEC Article 220.83:
The result shows total demand in amps and whether the current service (100A, 200A, etc.) can handle it. If an upgrade is needed, use the service price calculator to price the job with the right margin.
NEC 220.83 is the National Electrical Code standard for calculating electrical demand in existing homes. It uses demand factors to estimate a realistic power draw, recognizing that not every appliance runs at full capacity at the same time.
Any time you add a major electrical load to a home. Common triggers include EV charger installs, heat pump additions, hot tub hookups, or kitchen remodels. If the calculated total exceeds the panel rating, a service upgrade is required.
Most Level 2 EV chargers draw 30-50 amps. Because they run for long periods, they are considered a continuous load. You must include the full nameplate rating of the charger to ensure the home's service can support the additional demand.
No. According to NEC standards, a load calculation only includes the larger of the two loads (heating or cooling), since they do not run simultaneously. This calculator handles that automatically to give you the most accurate amperage result.
Accuracy prevents the two biggest issues in electrical work: undersizing a service, which leads to tripped mains and fire hazards, or over-quoting a customer for an upgrade they do not actually need. A reliable load calculation builds trust and ensures code compliance.