How Many Solar Panels Do I Need? Calculator
Estimate the solar array size and approximate panel count needed to match a chosen amount of electricity consumption.
Solar Panel Sizing Calculator
Estimated system size—
Approx. panels—
Average daily use—
Annual use—
Solar sizing formula
System kW ≈ Daily kWh ÷ [Peak sun hours × (1 − system losses)]
This is a first-pass estimate. Roof orientation, shading, module temperature, inverter clipping, local weather and export rules can materially change the final design.
Frequently asked questions
Can I size solar from my electric bill?
Yes. Annual kWh from your utility bills is a good starting point for a preliminary system size.
Why are peak sun hours important?
They translate local solar resource into an equivalent number of full-power hours per day.
Estimates only. Actual energy use and costs vary by equipment, climate, tariffs, installation conditions and user behavior.