NEC ReferenceNEC 2023 · 2026 · Updated May 2026

NEC Article 220: Dwelling Load Calculations

NEC Article 220: Load Calculations covers General Lighting Loads through Service Size. This guide explains each section with practical interpretation, common mistakes, and how these rules apply to real projects.

220.12 General Lighting Loads

Dwelling units use 3 VA per square foot of living area to calculate general lighting loads. A 2,000 sq ft home starts with 6,000 VA for general lighting. This figure covers all general-purpose receptacle outlets and lighting - it seems high for modern LED homes, but the NEC accounts for worst-case load scenarios and portable appliance use on general circuits.

The square footage is based on outside dimensions of the dwelling, not counting open porches, garages, or unused/unfinished spaces per 220.12.

220.52 Small Appliance and Laundry

Each of the two required kitchen small-appliance circuits counts as 1,500 VA per 220.52(A), totaling 3,000 VA. The laundry circuit adds another 1,500 VA per 220.52(B). These are fixed values regardless of how many appliances are actually plugged in - the NEC assumes a reasonable worst-case load per circuit.

For our 2,000 sq ft example: 6,000 (lighting) + 3,000 (small appliance) + 1,500 (laundry) = 10,500 VA before demand factors are applied.

220.42 General Lighting Demand Factors

Table 220.42 applies demand factors to the combined general lighting, small-appliance, and laundry load: the first 3,000 VA at 100%, and the remainder at 35% for dwelling units. For our 10,500 VA example: 3,000 VA at 100% = 3,000 + 7,500 VA at 35% = 2,625, totaling 5,625 VA after demand.

This steep reduction reflects the reality that not every light, outlet, and small appliance runs simultaneously. The demand factors are based on decades of statistical load data from actual homes.

220.53 Appliance Load

Fastened-in-place appliances (water heater, dishwasher, disposal, trash compactor, etc.) are added at nameplate rating. When four or more such appliances are present, a 75% demand factor applies per 220.53. Electric ranges use Table 220.55 demand factors: a single range rated up to 12 kW has a demand load of 8 kW per Column C.

Ranges over 12 kW add the excess above 12 kW to the 8 kW base. Dryers use 5,000 VA or the nameplate rating, whichever is larger, per 220.54. HVAC loads follow 220.60: use the larger of heating or cooling (not both), since they rarely operate simultaneously.

Calculating Service Size

Add all demand loads together and divide by 240V to get the service amperage. A worked example for a 2,000 sq ft home: after demand factors, general lighting = 5,625 VA, range (12 kW) = 8,000 VA, dryer = 5,000 VA, water heater = 4,500 VA, dishwasher + disposal = 2,400 VA (at 75% with 4+ appliances), central AC = 5,000 VA, EV charger = 11,520 VA.

Total: approximately 42,000 VA = 175A, requiring a 200A service. Without the EV charger, it drops to roughly 127A - still 200A service, since 150A panels are uncommon and the margin is too thin. Use our panel load calculator for your specific scenario.

Key NEC Tables Referenced

Frequently Asked Questions

What does NEC Article 220 cover?

Article 220 covers load calculations requirements. Key sections include 220.12 General Lighting Loads and 220.52 Small Appliance and Laundry. It applies to all electrical installations in the United States.

Where can I find the full text of Article 220?

The full NEC is published by NFPA and available at nfpa.org. Many libraries provide free access. Your local building department also has copies available for reference during permit applications.

Does Article 220 apply to existing wiring?

The NEC applies to new installations, modifications, and additions. Existing wiring that was code-compliant when installed is generally grandfathered unless a renovation triggers an upgrade requirement. Check with your local AHJ (authority having jurisdiction).

When did the current Article 220 requirements take effect?

NEC 2026 is the latest published edition (effective September 2025). NEC 2023 remains the most widely adopted edition by states. Adoption varies - check your state adoption status on our state code pages.

Requirements vary by state. NEC edition, licensing, permits, and GFCI rules differ by jurisdiction. Check your state or pick it below for personalized info across WireRef.
This guide provides practical interpretation of NEC requirements. Always verify with your local AHJ and the current NEC edition adopted in your jurisdiction. WireRef is a reference tool and does not replace licensed professional judgment.

NEC references verified May 2026