Calculator Inputs
Example Data Table
| Mode | Phase | Voltage (V) | Current (A) | PF | Efficiency (%) | Rated kVA | Hours | Fuel Rate (L/hr) | Output kVA | Output kW | Energy (kWh) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Electrical Inputs | Three Phase | 415 | 100 | 0.80 | 92 | 80 | 8 | 14 | 71.88 | 57.50 | 460.03 |
| This example yields about 43.13 kVAR reactive power, 62.50 kW estimated mechanical input, 5.00 kW losses, 112.00 litres fuel, and 140.00 total fuel cost when fuel is priced at 1.25 per litre. | |||||||||||
Formula Used
1) Apparent Power
Single phase: S (kVA) = V × I ÷ 1000
Three phase: S (kVA) = √3 × V × I ÷ 1000
2) Real Power
P (kW) = S (kVA) × Power Factor
3) Reactive Power
Q (kVAR) = √(S² − P²)
4) Mechanical Input and Losses
Mechanical Input (kW) = Real Power ÷ Efficiency
Losses (kW) = Mechanical Input − Real Power
5) Energy and Fuel
Energy (kWh) = Real Power × Operating Hours
Total Fuel (L) = Fuel Rate × Operating Hours
Fuel Intensity (L/kWh) = Total Fuel ÷ Energy
In rated mode, the tool first calculates kVA from rated capacity and selected load percentage, then derives current from voltage and phase type.
How to Use This Calculator
- Select Electrical Inputs if you know voltage and current, or select Rated Capacity if you want output from generator nameplate kVA and load percentage.
- Choose Single Phase or Three Phase. For three-phase systems, enter the line-to-line voltage.
- Enter the power factor and generator efficiency. These values strongly affect real power, losses, and fuel intensity.
- Provide operating hours to estimate total energy production.
- Add fuel rate and fuel cost to estimate total fuel use and running expense.
- Press Calculate Generator Output. The results will appear above the form, directly under the page header.
- Use the Download CSV or Download PDF buttons to save the report.
Frequently Asked Questions
1) What does this calculator measure?
It estimates generator apparent power, real power, reactive power, current, mechanical input, losses, energy output, fuel usage, and fuel cost from the values you enter.
2) When should I use electrical input mode?
Use electrical mode when you already know the operating voltage and line current. It is useful for checking real-world loaded performance during field measurements.
3) When should I use rated capacity mode?
Use rated mode when you know the generator nameplate kVA and expected load percentage. It helps during planning, sizing, budgeting, and pre-installation reviews.
4) Why does power factor matter?
Power factor determines how much of the apparent power becomes useful real power. Lower power factor reduces kW output for the same kVA level.
5) What do the losses represent?
Losses represent the estimated difference between mechanical input power and electrical output power. They reflect conversion inefficiencies inside the generator system.
6) Can this help identify overload conditions?
Yes. If you provide rated kVA, the calculator compares estimated apparent output against that rating and flags when the operating demand exceeds it.
7) Is fuel use always accurate?
Fuel results are only as accurate as the fuel rate you enter. Real consumption changes with engine tuning, load changes, ambient conditions, and maintenance quality.
8) Can I save the results for reports?
Yes. After calculation, use the built-in CSV and PDF buttons to export the current inputs and calculated results for documentation or sharing.