For US homes, RVs, vans & cabins. Size your system in minutes. No sign-up, no sales pressure.
Powerwall Calculator Off-Grid System CalculatorFree Powerwall 3 sizing calculator for whole-home backup. Most US homes need 2–3 units; small 1,100 sq ft homes need 2 (or 1 with solar). Includes installed cost from $14,800 and solar savings.
Open Powerwall CalculatorSolid background reading before you size or buy. Written by an electrical engineer.
Pick your setup and get a tailored calculator pre-loaded with typical appliances.
Specialised tools for batteries, DIY packs, EV charging, outage backup and winter sizing.
Enter your appliances and we'll size the whole system — panels, batteries, inverter, and charge controller.
Open System Calculator