When to use this: for sizing a residential service before design or remodel. The standard method (NEC 220.40-220.55) applies a 100% / 35% demand factor to the general lighting and small-appliance load and adds dryer, range, A/C, heat, and the largest motor on top. For planning only – confirm with a licensed electrician and your local jurisdiction.

Residential Load Calculator (NEC 220 Standard)

Standard-method dwelling load calculation per NEC Article 220, Part III. Inputs in volt-amperes (VA) where applicable.

Heated/conditioned area only. NEC 220.12: 3 VA/ft^2 general lighting.
NEC 210.11(C)(1): minimum two 20 A circuits at 1500 VA each.
NEC 210.11(C)(2): minimum one 20 A circuit at 1500 VA.
NEC 220.55: range <= 12 kW counts as 8 kVA demand.
NEC 220.54: minimum 5 kVA demand for one dryer.
Largest unit; A/C and heat are non-coincident, the larger wins.
Total fixed electric space-heating load. NEC 220.51.
NEC 220.50 / 430.24: add 25% of the largest motor.
Water heater, dishwasher, disposal, etc. (nameplate VA, sum).

Calculated load

General lighting + small-appliance + laundry—
After 220.42 demand factors—
Range demand (220.55)—
Dryer demand (220.54)—
A/C vs heat (larger of)—
Other fixed loads—
Largest motor + 25%—
Total calculated load (VA)—
Amps at service voltage—
Recommended service size—

Recommended service is rounded up to the next standard ampacity (100/125/150/200/225/300/400 A). NEC 230.79: minimum 100 A for a one-family dwelling.

Last reviewed: April 2026 (NEC 2023)

Tools we used or recommend for this work: a Klein receptacle tester to verify each circuit you load-counted, a Milwaukee M12 inspection camera for verifying conductor sizes inside the panel without pulling the dead-front, and a labeling kit (Brady or DYMO Rhino) for the panel schedule this calculator helps you build. Links may be affiliate-tagged where the brand has a program.

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