Solar and Battery Calculators

Every solar and battery calculator on the site, grouped by the job. Each one shows the formula and the steps with your numbers, keeps its inputs in the link so you can share or repeat a result, and prints a dated record. Nothing you type is uploaded.

Solar panels

• Solar panel calculator — how many solar panels you need, system size in kW, roof area and yearly output.
• Solar panel output calculator — kWh per day, month and year from panel watts and sun hours.
• Solar panel angle calculator — the best tilt for your latitude, by season or date.
• Solar charge controller calculator — MPPT or PWM controller amps and the cold-weather Voc check.
• Solar wire size calculator — PV string, controller and battery cable size by voltage drop.

Batteries

• Solar battery size calculator — battery bank Ah and kWh for off-grid and backup systems.
• Battery runtime calculator — how long a battery runs a load, including UPS batteries.
• Battery charging time calculator — hours to charge with a given charger.
• Amp hour calculator — Ah to Wh, Wh to Ah, and series or parallel battery banks.
• mAh to Wh converter — power bank watt-hours and the airline carry-on limit.
• Battery voltage chart — lead-acid state of charge from resting voltage.

Inverters

• Inverter size calculator — continuous and surge watts and the battery current.

All results are estimates for planning: check equipment data sheets and the applicable electrical code (such as NEC Article 690) and have critical designs verified. Results may be used freely in commercial work such as quotes, proposals and reports.