Generator Capacity Calculator
Size your generator based on total connected electrical load, demand factors, and future growth margins.
1. Add Connected Loads
| Load Description | Connected Watts | Action |
|---|---|---|
| No loads added yet. | ||
| Total Connected Load | 0 W | |
2. Apply Factors & Margins
Percentage of total load likely to be operating simultaneously.
Extra capacity for future loads or continuous duty buffer.
Typically 0.8 for standard generators, 1.0 for resistive loads.
Capacity Analysis
Total Connected Load
0 kW
Demand Load
x 0.8 Demand Factor
0 kW
Recommended Size
+ 25% Margin
0.0 kW
0.0 kVA
Load Comparison
How to Use
List every device you plan to power. Use the "Add Load" form to input the name and rated watts for each item.
Not all lights and appliances run at once. Lower the "Demand Factor" to reflect real-world simultaneous usage (NEC often allows < 100%).
Generators shouldn't run at 100% capacity continuously. Add a 20-25% safety margin to prolong equipment life.
Review the calculated "Required Generator" size in kW and kVA to select the right model for your needs.
Note: Watts = Volts × Amps. 1 kW = 1000 Watts. Demand calculations based on NEC 220 guidelines for general approximations.