How to use this calculator
Check the appliances you'll actually run on a normal day — the defaults cover a comfortable minimalist setup (lights, fridge, laptop, fan). Then set your peak sun hours and how many sunless days you want the batteries to carry you. The panel count updates instantly. Toggle the air conditioner on and off to see why AC is the single decision that determines your system size.
Frequently asked questions
How many solar panels does a tiny home need?
Most off-grid tiny homes land between 2 and 6 four-hundred-watt panels (800W–2.4 kW). A lights-and-fridge setup needs about 2; add a mini-split AC and you're at 6 or more. The calculator above sizes it to your actual loads instead of guessing.
What size battery bank does an off-grid tiny house need?
Take your daily watt-hours, multiply by the sunless days you want covered, and divide by 0.8 (since LiFePO4 batteries shouldn't be drained past 80%). A 1,555 Wh/day setup with 2 days of backup needs about 3.9 kWh of batteries — one standard 5 kWh unit.
How much does off-grid solar cost for a tiny home?
As a 2026 ballpark, a small DIY system (2 panels + one 5 kWh battery + inverter and hardware) runs roughly $2,500–$4,000. Add air conditioning and you're looking at $7,000–$10,000+. Professional installation roughly doubles the DIY number.
Can a tiny home run entirely on solar?
Yes — thousands do — with two honest caveats. First, size for winter sun hours, not summer, or December will humble you. Second, air conditioning is the load that breaks budgets; many off-gridders cool with shade, airflow, and a small fan instead.
Do I still need a generator?
Most off-grid tiny home owners keep one anyway. A week of storms will drain any reasonably sized battery bank, and a generator is cheap insurance. Size yours with our generator size calculator — the classic combo is solar for daily power, generator for the worst week of the year.