Calculator library
Solar and battery calculators
Each tool answers a different planning question. Inputs are processed in your browser, and every result lists the losses and assumptions used.
Battery sizing
Work from energy use, appliances, or a battery you already own.
Solar battery size and bank calculator
Turn daily energy and autonomy days into nominal kWh, Ah, and a whole-module battery bank.
Battery runtime calculator for Ah, Wh and watts
Estimate LiFePO4, AGM, and solar battery runtime from capacity, load watts, usable depth, and inverter losses.
Solar battery charging time calculator
Estimate equivalent charging sun and solar days from battery capacity, state of charge, panel watts, losses, and finishing-stage time.
Battery backup calculator
Build an appliance list and size the energy storage needed for an outage.
Battery wiring
Check how series and parallel connections change voltage and amp-hours.
Solar panels
Move between energy demand, array size, and expected output.
Solar panel series and parallel calculator
Calculate array Voc, Vmp, Isc, Imp, panel count, and optional cold-weather Voc.
Solar panel size and kWh calculator
Convert daily or monthly kWh into array watts and whole panels using peak sun hours and losses.
Solar panel roof space calculator
Compare portrait and landscape panel counts inside a measured usable roof rectangle.
Solar panel output calculator
Estimate daily, monthly, and yearly energy from an array you already have.
Solar panel efficiency calculator
Calculate rated module efficiency from panel watts, face area, and an explicit irradiance condition.
Solar charge controller calculator
Calculate cold-corrected array Voc, PV input current, output current, and minimum documented controller limits.
Solar panel tilt and azimuth calculator
Compare practical tilt and azimuth candidates with PVWatts location weather and quantify the modeled energy difference.
System planning
Combine load, storage, and solar requirements in one scenario.
Solar load calculator
Total appliance watts, quantity, daily run time, and listed surge before sizing batteries or panels.
Off-grid solar system calculator
Combine an editable appliance load, battery autonomy, solar coverage, panel count, and controller current baseline in one transparent plan.
RV solar calculator
Plan RV loads, battery storage, solar panels, and a controller current baseline together.