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NEC Load Calculation Scenario Simulator

Step-through NEC 220 residential load calculation · Code section at every step

TOTAL DEMAND LOAD

28.9 kVA

CALCULATED AMPERES

121 A

@ 240V single-phase

MINIMUM SERVICE

150A

NEC 230.79 standard size

Residential Parameters

Floor Area (sq ft)2,200

Small Appliance Circuits (min 2)2

Laundry Circuits (min 1)1

Range (W)12,000

Electric Dryer (W)5,500

HVAC Largest Load (W)3,600

Water Heater (W)4,500

Other Fixed Appliances (W)1,500

General Lighting (3 VA/sq ft)NEC 220.12

2200 sq ft × 3 VA = 6,600 VA

Connected

6,600 VA

Small Appliance CircuitsNEC 220.52(A)

2 circuits × 1,500 VA = 3,000 VA (min. 2 circuits)

Connected

3,000 VA

Laundry Circuit(s)NEC 220.52(B)

1 circuit(s) × 1,500 VA = 1,500 VA (min. 1 circuit)

Connected

1,500 VA

Apply Demand Factor (Steps 1–3)NEC 220.42 Table

First 3,000 VA at 100%, next up to 120,000 VA at 35%. Combined: 11,100 VA → 5835 VA

Connected

5,265 VA

Running Demand Total: 5.8 kVA

Range / Cooking EquipmentNEC 220.55

Nameplate: 12.0 kW → demand: 8.0 kW (NEC 220.55 Col C, single unit)

Connected

12,000 VA

Running Demand Total: 13.8 kVA

Electric DryerNEC 220.54

Nameplate: 5.5 kW, 100% demand (single unit, min 5 kVA)

Connected

5,500 VA

Running Demand Total: 19.3 kVA

Largest HVAC LoadNEC 220.60

Heating or cooling (whichever is larger): 3.6 kW at 100%

Connected

3,600 VA

Running Demand Total: 22.9 kVA

Fixed Appliances (Water Heater + Other)NEC 220.53

Water heater: 4.5 kW + other: 1.5 kW. 75% demand if ≥4 appliances.

Connected

6,000 VA

Running Demand Total: 28.9 kVA

Minimum Service Entrance SizeNEC 230.79

Total demand: 28.9 kVA ÷ 240V = 121 A → select 150A service

Running Demand Total: 28.9 kVA

→ 150A Service