Free tool · NEC Article 220

Dwelling Load Calculator

Calculate residential general loads by the NEC Article 220 standard method — general lighting, small-appliance, and laundry, with the demand factors applied and the worked steps.

General lighting + two small-appliance circuits + laundry, then the Article 220 demand factors (first 3,000 VA at 100%, the rest at 35%). General loads only.

Calculated demand (general loads)

5,415VA

General lighting (1,800 × 3)5,400 VA
Small-appliance (2 × 1,500)3,000 VA
Laundry1,500 VA
Subtotal9,900 VA
After demand (3,000 + 35% rest)5,415 VA

≈ 22.6 A at 240 V — add appliance, HVAC, and range loads for the full service calculation.

How to calculate a dwelling load (NEC Article 220)

  1. 1

    General lighting load

    Multiply the dwelling's square footage by the NEC general lighting unit load — 3 VA/sq ft under the 2023 NEC, 2 VA/sq ft under the 2026 NEC (220.41 / 220.12).

  2. 2

    Add small-appliance and laundry circuits

    Add two small-appliance branch circuits at 1,500 VA each (3,000 VA total) and one laundry circuit at 1,500 VA — required by 210.11(C) and counted in 220.52.

  3. 3

    Apply the demand factors

    Under the standard method, the first 3,000 VA of these general loads is taken at 100% and everything above 3,000 VA at 35% (Table 220.45). Divide the result by the service voltage for amps.

Dwelling load — frequently asked questions

How do you calculate a dwelling load?

Under the NEC standard method (Article 220): general lighting = square footage × the unit load (3 VA/sq ft in 2023, 2 VA/sq ft in 2026), plus two 1,500 VA small-appliance circuits and one 1,500 VA laundry circuit. Then apply the demand factors — first 3,000 VA at 100%, the remainder at 35%. Add fixed appliances, range, dryer, and HVAC separately for the full service size.

What is the general lighting load per square foot?

The NEC general lighting unit load for a dwelling is 3 volt-amperes per square foot under the 2023 NEC and 2 VA/sq ft under the 2026 NEC. It's based on the outside dimensions of the dwelling, not including unfinished spaces not adaptable for future use.

What's the difference between the standard and optional methods?

The standard method (220 Part III) totals each load category and applies individual demand factors. The optional method (220.82) lets a dwelling apply a simpler demand calculation — 100% of the first 10 kVA of general load and 40% of the remainder, plus heating/AC. This calculator uses the standard-method general loads.

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