Solar Inverter Size Calculator
Estimate a preliminary solar inverter AC rating from array power, target DC-to-AC ratio, continuous load, surge load and growth allowance.
Default project preview
9.17 kW AC
Array-driven AC rating
8.33 kW
Load-driven AC rating
7 kW
Estimated surge capability
13.75 kW
Nominal efficient AC output
8.8 kW
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Array-driven rating = DC array power ÷ target DC/AC ratio. The calculator compares that value with continuous load, adds growth allowance and checks the entered surge multiplier.
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Solar Inverter Size Calculator questions
Why can the inverter be smaller than the solar array?+
Solar arrays rarely operate at nameplate power continuously, so many systems use a DC array rating larger than the inverter AC rating.
Is surge power the same as continuous power?+
No. Motors and pumps may need brief starting power above their running load, and inverter surge duration varies by model.
Does this select string voltage or battery voltage?+
No. Voltage compatibility and string design require equipment-specific electrical calculations.