Solar Inverter Size Calculator
Match an inverter to your solar panel array.
Your result
Enter your numbers and press the button. Your result appears here.
Inverters are often a little smaller than the panel array because panels rarely reach their full rating. A DC-to-AC ratio of 1.1 to 1.3 is common.
How it works
Inverter AC size = panel array DC size ÷ DC-to-AC ratio.
Example: a 8.0 kW array at a 1.2 ratio needs about a 6.7 kW inverter.
At a glance
Same settings as the calculator, changing only the system size.
| System size | Inverter | Panels |
|---|---|---|
| 4 kW | 3.3 kW AC | 10 |
| 6 kW | 5.0 kW AC | 15 |
| 8 kW | 6.7 kW AC | 20 |
| 10 kW | 8.3 kW AC | 25 |
| 12 kW | 10.0 kW AC | 30 |
| 15 kW | 12.5 kW AC | 38 |
Common questions
Can the inverter be smaller than the panels?
Yes. Panels rarely reach their rated output, so arrays are often 10% to 30% larger than the inverter. Stay within the inverter's DC input limits.
Microinverters or a string inverter?
Microinverters sit under each panel and suit shaded or complex roofs. A string inverter costs less on simple, unshaded roofs.