How the calculation works
No proprietary scoring, no black box. The Ghost Load Auditor runs the two residential optional-method load calculations written into the North American electrical codes, with every demand factor applied exactly as published. This page documents the method so you — or your electrician — can check the work.
United States — NEC 220.82 Optional Method
For an existing dwelling on a 120/240 V service, NEC 220.82 (2023 edition) builds the load in two parts:
General loads — 220.82(B)
Lighting at 3 VA per square foot, two small-appliance circuits and one laundry circuit at 1,500 VA each, plus every fixed appliance at 100% nameplate. The first 10,000 VA of that total counts at 100%; everything above it at 40%.
Heating & cooling — 220.82(C)
The LARGEST of: the air conditioner, the heat pump compressor, the compressor plus 65% of supplemental electric heat, or 65% of electric space heating. Heating and cooling are never summed — the worst single case governs.
EV charging
Counted at 100% nameplate, or excluded when an energy management system controls it.
We apply NEC 2023 values by default. A proposed 2026 amendment would lower the first tier to 8,000 VA and lighting to 2 VA/ft² — the tool never applies 2026 values unless explicitly selected, because the default is what your inspector uses today. NEC 220.82 is self-contained: no additional motor surcharges are added on top of it.
Canada — CEC Rule 8-200 (26th Edition)
Basic load
5,000 W for the first 90 m² of living area, plus 1,000 W for each additional 90 m² or portion of it.
Range & large appliances
An electric range counts at 6,000 W plus 40% of any nameplate above 12 kW. When a range is present, other loads over 1,500 W (dryer, water heater, make-up air heater) count at 25%; with no range, they count at 100%.
Space heating & cooling
Heating per Rule 62-118(3): first 10,000 W at 100%, remainder at 75%. Then Rule 8-106(3): the GREATER of heating demand or cooling counts — never both.
Minimum floor & EV
Total demand is never below 24,000 W for homes of 80 m² or more (14,400 W below that). EV charging counts at 100% nameplate unless an EVEMS per Rule 8-500 controls it.
The verdict line
Both methods end at the same comparison: calculated demand in amps against 80% of your service rating — the continuous limit. Under it: PASS. Between 80% and 100%: WARN, the band where load management and right-sizing decide the outcome. Over 100%: FAIL, and the recommendation is a service upgrade capped at 200 A — the practical residential maximum — or load reduction. We anchor to the 80% limit, never the raw panel rating, because continuous loads are what heat pumps are.
What this tool does not do
- It does not inspect your home — results are only as complete as the loads you enter.
- It does not replace the official load calculation an electrician files with your permit.
- It does not recommend contractors, and no contractor pays to appear here.
- It uses industry-average nameplate values where you don't know exact figures — good for a screening estimate, not a design document.
Treat every result as a well-informed starting point that lets you walk into quotes knowing your numbers.
Who checked this math
A Red Seal Refrigeration Mechanic · Red Seal Plumber · Class A Gas Fitter with 25+ years of commercial and industrial HVAC/R experience across Western Canada. The engines behind this tool are the same ones running the panel audit at HeatPumpLocator.com, kept in lockstep so both properties always give the same answer for the same home.