Residential Load Calculator

Calculate single-family and multifamily residential electrical service load using NEC 2026 Article 120 (formerly Article 220) standard & optional methods with 2026/2023 dual citations.

NEC edition

Inputs

ft²

Conditioned floor area of the dwelling (outside dimensions)

Three-phase services divide by √3 × line voltage, not by the phase voltage

Fixed Appliances

circuits

Minimum 2 per §120.13

circuits
VA

Nameplate or 12 kVA if not known

VA

Nameplate or 5 kVA minimum (§220.54)

VA
VA

Nameplate; compare to heat load — use larger

VA

For a heat pump, enter the supplemental/backup strip heat here and the compressor under Air conditioning

§220.82(C) applies a different percentage to each of these

VA
qty

§220.53: where four or more are fastened in place, that group takes a 75% demand factor. Ranges, dryers, space heating and A/C are not counted.

VA

§220.50 / §430.24: 25% of the largest motor is added to the service calculation

qty

Table 220.55 Column C is applied to this count

EVSE (EV Charger)

qty
VA

NEC 2026 §120.57: use nameplate @ 100%; 7,200 VA minimum if unknown

Calculation Method

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⚡ Test your knowledge
NEC Article 220 was renumbered in the 2026 code cycle. What is the new article number?
  • A. Art. 100
  • B. Art. 120
  • C. Art. 200
  • D. Art. 230
💡 NEC 2026 renumbered Article 220 (Branch-Circuit, Feeder, and Service Calculations) to Article 120.
Energy Management Systems were moved from Article 750 to which article in NEC 2026?
  • A. Art. 100
  • B. Art. 125
  • C. Art. 130
  • D. Art. 150
💡 NEC 2026 moved Energy Management Systems from Article 750 to Article 130.
Which NEC standard size overcurrent device comes after 90A?
  • A. 95A
  • B. 100A
  • C. 110A
  • D. 105A
💡 Per NEC §240.6(A), the standard sizes are …90, 100, 110, 125… There is no 95A standard size.

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How it works & the NEC rules behind it

In the NEC 2026 edition, the entire calculation framework for branch circuit, feeder, and service calculations was renumbered from Article 220 to Article 120. Key technical updates include the reduction of general residential lighting load and modified demand thresholds for EVSE and heat pumps.

Major NEC 2026 vs 2023 Code Changes:

  • General Lighting Load (§120.41 vs §220.12): Sizing general lighting for service and feeder calculations dropped from 3 VA/sq ft to 2 VA/sq ft in recognition of universal energy-efficient LED adoption. (Note: Branch-circuit layout still uses 3 VA/sq ft).
  • Optional Method Tier 1 (§120.82 vs §220.82): The 100% first tier in the single-family optional method is updated to 8,000 VA @ 100% (plus remainder at 40%) in NEC 2026, compared to 10,000 VA in 2023.
  • Electric Vehicle Supply Equipment (§120.57): EV charging loads are calculated using nameplate rating @ 100% (minimum 7,200 VA if unknown), unless managed by an Energy Management System (EMS) per Article 750 / Article 130.

Formulas & equations

Standard Method: Total VA = Lighting/SA/Laundry Demand + Fixed Appliances + Range + Dryer + HVAC + EVSE Optional Method: Total VA = [First 8 kVA @ 100% + (Remainder Loads × 40%)] + Max(Heat, AC) + EVSE Service Amperes = Total VA / Nominal Service Voltage (e.g. 240V)
Standard Demand Factors (§120.44 / §220.42):
• First 3,000 VA of general load @ 100%
• 3,001 to 120,000 VA @ 35%
• Remainder above 120,000 VA @ 25%

NEC reference table

Calculation Parameter NEC 2026 (New Article 120) NEC 2023 (Former Article 220) Practical Impact
General Lighting 2.0 VA / sq ft (§120.41) 3.0 VA / sq ft (§220.12) Lowers calculated service load by 2,000–3,000 VA on typical homes.
Small Appliance & Laundry 1,500 VA / circuit (min 3 circuits) 1,500 VA / circuit (min 3 circuits) Unchanged (2 kitchen small appliance + 1 laundry required).
Optional Method Tier 1 8,000 VA @ 100% (§120.82) 10,000 VA @ 100% (§220.82) Shifts more load into the 40% demand tier.
EVSE (EV Chargers) Nameplate @ 100% (min 7.2 kVA) 7,200 VA @ 125% Coordinates with new Article 130 Energy Management Systems.

Worked example, step by step

Example Calculation: 2,400 sq ft Single-Family Home (240V Service)

Given: 2,400 ft² home, 2 Small Appliance circuits, 1 Laundry, 12 kVA Range, 5 kVA Dryer, 4.5 kVA Water Heater, 5 kVA Central A/C, 10 kVA Fixed Heat, 1 Level 2 EVSE (7.2 kVA).

  • Step 1 (General Load): Lighting = 2,400 × 2 = 4,800 VA. Small Appliance + Laundry = 3 × 1,500 = 4,500 VA. General Total = 9,300 VA.
  • Step 2 (Appliance Loads): Range (8,000 VA per T.220.55), Dryer (5,000 VA), Water Heater (4,500 VA).
  • Step 3 (Optional Method): Total non-HVAC loads = 9,300 + 8,000 + 5,000 + 4,500 = 26,800 VA.
    • First 8,000 VA @ 100% = 8,000 VA
    • Remainder (18,800 VA) @ 40% = 7,520 VA
    • Subtotal = 15,520 VA
  • Step 4 (HVAC & EVSE): Larger of Heat (10 kVA) or AC (5 kVA) = 10,000 VA. EVSE = 7,200 VA.
  • Total Service Load: 15,520 + 10,000 + 7,200 = 32,720 VA.
  • Service Amperage @ 240V: 32,720 VA / 240V = 136.3 Amps → Standard 200A Service Panel required.

Frequently asked questions

The standard method (NEC §120.40–§120.60 / §220.40) itemizes each branch load with specific demand factor tables for cooking, dryers, and lighting. The optional method (§120.82 / §220.82) simplifies this by combining all general lighting, small appliance, and fixed equipment into a single bucket (First 8 kVA @ 100%, remainder @ 40%) plus HVAC and EVSE. The optional method typically yields a lower, more realistic service size for single-family homes.

A typical Level 2 EV charger draws 32A to 48A (7.7 kW to 11.5 kW). If your home currently has a 100A or 125A service with electric heat or central AC, adding an EV charger will often push total calculated demand past 100A, requiring either a service upgrade to 200A or an automated Energy Management System (EMS) / load shed device.

NFPA restructured Chapter 1 and Chapter 2 of the NEC for the 2026 cycle to improve logical flow. General wiring requirements and calculation standards were reorganized, moving load calculations into new Article 120, while introducing Article 130 for Energy Management Systems.

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