Sizing an off grid solar system means matching what you use each day to what your panels can generate and what your battery can store. This calculator does both jobs. Enter your daily energy use in watt hours, the peak sun hours your location gets, the system voltage of your battery bank, and how many days of backup you want, and the tool returns the solar array wattage you need and the battery capacity in amp hours. It adds a system loss margin for wiring, charge controller and inverter inefficiency, and it derates the usable battery capacity so you do not discharge lead acid or lithium cells too deeply. This helps you plan a cabin, an RV, a boat or a backup power setup without guesswork. Enter your numbers and read a practical starting specification instantly. Everything runs locally in your browser, so it is private and immediate.
Sizing an off grid solar system means matching what you use each day to what your panels can generate and what your battery can store. This calculator does both jobs.
Yes. Solar Panel and Battery Sizing Calculator is completely free, with no sign-up and no usage limits.
Yes. Solar Panel and Battery Sizing Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Solar Panel and Battery Sizing Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.