# DC/AC Ratio (oversizing)

The ratio between the array's rated DC capacity in watt-peak and the inverter's nominal AC power. A ratio above 1.0 means the array is deliberately oversized relative to the inverter, which is standard practice rather than a design error.

Source: https://inverterdata.com/en/glossary/dc-ac-ratio/
Site: InverterData (inverterdata.com) — open technical specification database
Last updated: 2026-08-24
License: free to quote with attribution to inverterdata.com

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Arrays are rated at standard test conditions that real roofs rarely see: modules run hotter, dirtier and at lower irradiance than the laboratory, so a nominally 6 kWp array seldom delivers 6 kW. Oversizing fills more of the inverter's operating range through the morning and afternoon and improves its efficiency at partial load, at the cost of **clipping** a small number of peak hours. Residential designs commonly sit somewhere between 1.1 and 1.3, with higher ratios justified on east-west roofs, in cloudier climates or where export is capped anyway. Always confirm the manufacturer's maximum permitted DC input power — exceeding it may affect the warranty.