Estimate the panel wattage, battery capacity, charge controller and inverter size for your off-grid, RV, marine or backup power system. This is a planning estimate — for critical or grid-tied systems, confirm sizing with a licensed installer.
Enter your details and click “Calculate My System” to see recommended component sizing.
Solar array: daily kWh ÷ peak sun hours ÷ 0.8 (system losses) = recommended array wattage.
Battery bank: daily kWh × days of autonomy ÷ 0.5 (usable depth of discharge) = usable capacity needed, converted to Ah at your system voltage.
Charge controller: array wattage ÷ system voltage × 1.25 (safety margin) = minimum controller amperage.
Inverter: peak simultaneous load × 1.25 (surge margin), rounded to the next common inverter size.