Solar battery size calculator
Estimate usable and nominal battery capacity, inverter size, runtime, and budget.
Updated 2026-07-15 · Formula version is shown with every result.
Data confidence
Early estimate
Evidence used
Uses backed-up load, runtime, surge, efficiency, chemistry, and depth-of-discharge assumptions.
What can vary
Battery controls, temperature, age, surge duration, and installer design require confirmation.
Your inputs
Use realistic values. Nothing is sent to an ad network.
Your estimate will appear here
Results include ranges, supporting metrics, formula version, assumptions, and warnings.
How this estimate works
SolarGabay uses pure, versioned TypeScript formula modules. The calculator normalizes inputs, rejects invalid values, and presents planning ranges instead of false precision.
Results are decision-support estimates. Confirm utility rates, supplier specifications, site conditions, and professional requirements before committing money. Review the methodology and source policy before treating any estimate as decision-ready.