Solar Inverter Sizing Calculator

Calculate the appropriate inverter size for your solar power system based on your power requirements, including continuous loads and surge demands.

Total power of all devices running simultaneously
Highest starting power needed (motors, pumps, etc.)
Battery bank or system voltage
Typical efficiency is 92-96%
Typical power factor is 0.8 to 0.9
Additional capacity for future needs

How to Use This Calculator

  1. Continuous Load: Enter the total wattage of all devices that run simultaneously.
  2. Surge Load: Input the highest starting power requirement of your equipment.
  3. System Voltage: Select your battery bank or system voltage.
  4. Inverter Efficiency: Account for power losses in the inverter.
  5. Power Factor: Consider the relationship between real and apparent power.
  6. Future Expansion: Add capacity for future power needs.

Understanding the Results

  • Minimum Inverter Size: The smallest inverter size that meets your current needs.
  • Recommended Size: Suggested inverter size including future expansion.
  • Maximum Current Draw: Peak current draw from your battery bank.

Important Considerations:

  • Choose an inverter with surge capacity at least 2-3 times the continuous rating
  • Consider pure sine wave inverters for sensitive electronics
  • Match inverter voltage to your battery bank voltage
  • Account for temperature derating in hot climates
  • Verify compatibility with your charge controller and batteries

For critical applications, consult with a solar professional to verify calculations.