Solar & Off-Grid Calculator

Comprehensive calculators for planning your off-grid life and solar power system

SolarRatio is a free, comprehensive calculator hub for solar and off-grid system design. From panel sizing and battery bank to inverter selection, wire gauge, charge time, solar ROI, and optimal tilt angle — covering everything from grid-tied savings to fully off-grid system design. Built for real-world conditions including local PSH, LiFePO4 and AGM battery characteristics, and regional solar irradiance variation. In the US, the federal Investment Tax Credit (ITC) currently covers 30% of installed system cost through 2032, and peak sun hours range from 3.7 h/day in Seattle to 6.5 h/day in Phoenix — factors that dramatically shift both your panel wattage requirement and your payback period. Whether you're sizing a rooftop grid-tie system in California, a Texas hill country off-grid cabin, or a Colorado mountain van build, every calculator here accounts for the geographic and regulatory variables that generic tools ignore.