Calculator
Inverter continuous & surge watts
Size the inverter continuous and surge ratings for your simultaneous AC loads, with headroom for motor starting surges.
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Looking for a definition or a quick answer? See the solar & battery glossary for terms used on this page, or the FAQ for common sizing questions. For the full explanation, read the continuous vs. surge watts guide.
Sources & standards
- UL 1741 — Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources — Safety and grid-interconnection standard for solar/battery inverters.
- IEEE 1547-2018 — Interconnection and Interoperability of Distributed Energy Resources — Technical requirements for connecting solar-plus-storage systems to the utility grid.
- NFPA 70 — National Electrical Code (NEC), Articles 690 & 705 — Governs PV source/output circuits (Art. 690) and interconnected power production sources (Art. 705) in the US.
Estimates for planning only. Verify with a meter and follow NEC / local code; have a licensed installer confirm any system before purchase or wiring. See the methodology for formulas and sources.