Electrical Load Calculator
Calculate the total electrical demand for a residential service using NEC Article 220 standard calculation methods. Determine the right panel size for your project.
Hot tub, pool pump, workshop equipment, etc.
Results
Total Demand
36,700
VA
Service Amps
153
Amps @ 240V
Recommended Panel
200A
Service Panel
Panel Size Analysis
Red line = NEC 80% continuous load limit. Panels should not be loaded beyond 80% of their rating for continuous loads.
| Panel Rating | 80% Max Load | Your Load | Status |
|---|---|---|---|
| 100A | 80A | 153% | Too small |
| 125A | 100A | 122% | Too small |
| 150A | 120A | 102% | Too small |
| 200A | 160A | 77% | Recommended |
| 400A | 320A | 38% | Acceptable |
Standard for modern homes. Good capacity for future loads like EV charging.
Suggested Circuit Layout
Based on NEC requirements for a 2,000 sq ft home. Total estimated circuits: 16.
General Purpose Circuits
| Circuit Type | Qty | Breaker | Wire Size |
|---|---|---|---|
| Lighting Circuits | 4 | 15A / 120V | #14 AWG |
| Kitchen Small Appliance | 2 | 20A / 120V | #12 AWG |
| Laundry | 1 | 20A / 120V | #12 AWG |
| Bathroom | 1 | 20A / 120V | #12 AWG |
| General Receptacles | 4 | 20A / 120V | #12 AWG |
Dedicated Circuits (240V)
| Appliance | Breaker | Wire Size |
|---|---|---|
| Electric Dryer | 30A / 240V | #10 AWG |
| Electric Range/Oven | 40A / 240V | #8 AWG |
| A/C or Heat Pump | 30A / 240V | #10 AWG |
| Water Heater | 20A / 240V | #12 AWG |
Circuit counts are estimates based on NEC minimums and industry best practice. Actual layout depends on room count, local code amendments, and inspector requirements. Always verify with a licensed electrician.
Service Entrance Sizing
Based on your 200A panel, per NEC Table 310.12 for 75°C-rated conductors.
Conductor Size
#2/0 AWG
Copper (or #4/0 AWG Aluminum)
Minimum Conduit
2"
Trade size (EMT/PVC)
Service Rating
200A
240V single-phase
Conductor sizes are for copper at 75°C rating. Aluminum alternatives shown in parentheses. Actual sizing may vary based on distance from meter to panel (voltage drop), ambient temperature, and conduit fill. Consult NEC Chapter 3 and your local AHJ for final requirements.
How to Use This Calculator
Enter the home's square footage for the general lighting load (3 VA per sq ft per NEC). Add the number of small appliance circuits (minimum 2 per NEC), laundry circuit wattage, and the wattage of major appliances. The calculator applies NEC demand factors to determine total service load and recommends a panel size.
Formula Used
General Lighting = Sq Ft × 3 VA. First 10,000 VA at 100%, remainder at 40%. Add AC/Heat (larger of the two at 100%), plus appliances. Total Amps = Total VA / 240V.
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Disclaimer
This calculator is for estimation purposes only. Results may vary based on local conditions, materials, and building codes. Always consult a licensed professional before making decisions based on these calculations. MyContractorTools is not responsible for any errors or omissions.