Inverter Sizing Calculator — Formula
## Solar Inverter Sizing
The inverter converts DC power from solar panels to AC power for home or grid use. It is typically sized smaller than the total panel capacity.
### Formula
**Inverter Size (W) = Total Panel Wattage / DC-to-AC Ratio**
A DC-to-AC ratio of 1.1-1.3 is standard. This means the inverter is smaller than the panel array. This is efficient because panels rarely produce their full rated power simultaneously. A ratio of 1.2 means 20% overbuilding on the DC side, which captures more energy during low-light hours with minimal clipping losses at peak.
The inverter converts DC power from solar panels to AC power for home or grid use. It is typically sized smaller than the total panel capacity.
### Formula
**Inverter Size (W) = Total Panel Wattage / DC-to-AC Ratio**
A DC-to-AC ratio of 1.1-1.3 is standard. This means the inverter is smaller than the panel array. This is efficient because panels rarely produce their full rated power simultaneously. A ratio of 1.2 means 20% overbuilding on the DC side, which captures more energy during low-light hours with minimal clipping losses at peak.
Esempio Risolto
An 8 kW (8,000 W) panel array with a 1.2 DC-to-AC ratio.
- Inverter size = 8,000 / 1.2 = 6,667 W
- That is a 6.67 kW inverter
- DC oversize headroom = (1.2 - 1) x 100 = 20%