What is the NEC 220.82 load calculation?

NEC 220.82 is the optional load calculation for a single dwelling with at least 100 amp service. Total the general loads, take the first 10 kVA at 100 percent and everything beyond at 40 percent, then add the larger of the heating or cooling load at its own demand factor.

General loads means 3 VA per square foot, 1,500 VA per small-appliance and laundry circuit, and every fixed appliance at nameplate.

It usually produces a smaller answer than the standard method, which is exactly why it exists; real houses never run everything at once.

Its sibling 220.87 lets you use a year of recorded demand data instead, which is the cleanest way to justify adding an EV charger to an existing service.

The NEC 220 calculator runs both methods side by side so you can use the friendlier result.