How do you calculate a residential electrical service load?

A residential electrical service load calculation starts with general lighting load based on dwelling floor area, adds required small-appliance and laundry circuits, includes fixed appliances such as range, dryer, water heater, EV equipment, heating, and air conditioning, then applies the demand factors allowed by the applicable NEC method before converting volt-amperes to amperes.

What changed for dwelling load calculations in the 2026 NEC?

The 2026 NEC reorganizes load-calculation content into Article 120 and updates dwelling calculation structure, including an optional-method example where the first 8 kVA threshold and 2 VA per square foot lighting value can reduce the calculated load for many typical dwelling units, subject to local adoption and amendments.

Load Calculator

Calculate total load for residential or commercial service.

NEC Edition

2023 NEC2026 NEC

Article 220 · 3 VA/ft² · First 10 kVA @ 100%, remainder @ 40%

Floor Area (sq ft) — General Lighting @ 3 VA/ft²Small Appliance CircuitsLaundry CircuitsRange / Oven (VA)Dryer (VA)Water Heater (VA)EV Charger / Other Equipment (VA)

Level 2 EVSE (240V): 30A circuit = 7,200 VA · 40A circuit = 9,600 VA · 50A circuit = 12,000 VA

Heating Load (VA)Cooling / A/C Load (VA)

Heating vs. Cooling: only the larger value is used per NEC 220.60.

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Worked Example — 2026 NEC Optional Method (Article 120)

The following example walks through a 2,000 sq. ft. dwelling unit using the 2026 NEC Optional Method. The key training point is that load calculation rules have been reorganized from Article 220 into Article 120 in the 2026 NEC cycle, so electricians should verify the adopted edition before using a calculator result. [Source: NEC 2026 Article 120; Source: NEC 2023 Article 220]

Scenario Parameters

Floor Area2,000 ft²

Small Appliance Circuits2 circuits × 1,500 VA

Laundry Circuit1 circuit × 1,500 VA

Electric Range12,000 VA (12 kVA)

Electric Dryer5,000 VA (5 kVA)

Heating (larger than A/C)15,000 VA (15 kVA)

Step 1 — General Loads (NEC 120.12 + 120.52)

General Lighting: 2,000 ft² × 2 VA/ft² = 4,000 VA
Small Appliance: 2 circuits × 1,500 VA = 3,000 VA
Laundry: 1 circuit × 1,500 VA = 1,500 VA
Total General Load: 4,000 + 3,000 + 1,500 = 8,500 VA

Step 2 — Apply Demand Factors (NEC 120.30 — Optional Method)

First 8 kVA @ 100%: 8,000 VA
Remainder (500 VA) @ 40%: 500 × 0.40 = 200 VA
Net General Load: 8,000 + 200 = 8,200 VA

Step 3 — Fixed Appliances & HVAC

Range: 12,000 VA
Dryer: 5,000 VA
Heating (larger than A/C): 15,000 VA
Appliances + HVAC subtotal: 32,000 VA

Step 4 — Total Calculated Load

8,200 VA (general) + 32,000 VA (appliances/HVAC) = 40,200 VA

Step 5 — Determine Service Size

Amps = Total VA ÷ Voltage = 40,200 ÷ 240 = 167.5 A
Round up to the next standard service size:
→ 200 Amp Service Required

2023 vs. 2026 NEC — Key Differences

Feature2023 NEC2026 NEC

Code LocationArticle 220Article 120

General Lighting3 VA/ft²2 VA/ft²

Optional Method TiersFirst 10 kVA @ 100%First 8 kVA @ 100%

Continuous Loads125% in load calc125% for OCPD/wire only

Power Control SystemsArticle 750 (limited)Article 130 (expanded)

The answers we give you are for educational purposes only. Please verify with your code book, your journeyman or master electrician, and your local Authority Having Jurisdiction (AHJ).