Plan reliable home backup
Inverter Size Calculator
Estimate planning inverter capacity from your connected load, safety margin and power factor.
Smart result
Your inverter estimate will appear here
—based on your details
We will turn the inputs into a clear answer, explain what drives it, and show what to do next.
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Frequently asked questions
How much safety margin should I use?+
The editable margin allows normal headroom. Motor starting surge and simultaneous peak loads may require separate professional sizing.
Why is inverter capacity shown in VA?+
Inverters are commonly rated in VA. The calculator converts design watts using the entered power factor.
Is this enough for motors or pumps?+
Not by itself. Confirm starting surge and manufacturer requirements for motor loads.