Solar Panel Calculator
Estimate how many solar panels you need based on your daily energy consumption, panel wattage, and peak sun hours.
US avg: 4–6 hrs
Enter energy usage and panel details.
How It's Calculated
System size (kW) = Daily kWh / Peak sun hours
Number of panels = System size / Panel wattage
Number of panels = System size / Panel wattage
A typical US home uses 30 kWh/day. With 400W panels and 5 peak sun hours, you'd need about 15 panels.
Example: 30 kWh/day ÷ 5 hrs = 6 kW system
6,000 W ÷ 400 W/panel = 15 panels
6,000 W ÷ 400 W/panel = 15 panels
FAQ
What are peak sun hours?
Peak sun hours are the equivalent hours of full-strength sunlight per day. This varies by location and season (typically 3–7 hours in the US).
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Last updated: 2026-08-08