Diesel Generator Sizing Calculator
Accurately size your diesel generator for various loads and applications.
Diesel Generator Sizing Calculator
Compliant with ISO 8528 Standards
Results:
Required Generator Size (kVA): 0.00
Required Generator Size (kW): 0.00
How to Use the Calculator
Input Load Details
- Enter the total connected load in Kilowatts (kW).
- Specify the Power Factor (PF) of your load (typically 0.8 for inductive loads).
Apply Safety Factor
- Enter a Safety Factor percentage (e.g., 25% for a 1.25 multiplier).
- This accounts for future expansion, transient loads, and derating.
- A common safety factor is 20-30%.
Get Results
- Click "Calculate" to see the required generator size in kVA and kW.
- The calculator considers both continuous and starting loads.
- Use "Reset" to clear all fields and start a new calculation.
Diesel Generator Sizing Fundamentals
Understanding kVA and kW
Generators are rated in both kVA (apparent power) and kW (real power). kW is the actual power consumed by the load, while kVA is the total power the generator can produce. The relationship is defined by the Power Factor.
Key Considerations:
Total Load (kW): Sum of all continuous loads.
Power Factor (PF): Ratio of real power to apparent power (kW/kVA).
Safety Factor: Additional capacity for future growth, derating, and transient loads.
Calculation Formulas
Apparent Power (kVA) from Load:
kVA_Load = Total_Load_kW / PF
Required Generator kVA:
Gen_kVA = kVA_Load × (1 + Safety_Factor_%)
Required Generator kW:
Gen_kW = Gen_kVA × PF
Example Calculation
Scenario: Small industrial facility
Total Connected Load: 80 kW
Power Factor: 0.8
Safety Factor: 25%
kVA_Load = 80 kW / 0.8 = 100 kVA
Gen_kVA = 100 kVA × (1 + 0.25) = 125 kVA
Gen_kW = 125 kVA × 0.8 = 100 kW
Required Generator Size: 125 kVA / 100 kW