Pre-filled with the national average cost per watt for a 4kW system ($3.40/W) — adjust to match your local market and quote.
Larger systems typically cost less per watt since fixed costs (permits, a truck roll, an inverter) spread across more capacity — this reference number reflects that economy of scale, not a flat national rate.
A 4kW system is a common size for a smaller home or lower-usage household, and its cost per watt reflects typical installer pricing at this scale — larger systems generally see somewhat lower $/W due to fixed costs spreading across more capacity. Check your actual usage against this size with the full solar panel calculator, or see the cost per watt calculator to benchmark a specific quote.
It depends entirely on your usage — a 4kW system produces roughly 5,200 kWh a year at average sun hours, which you can compare against your actual annual usage from a utility bill or the kWh usage from bill calculator.
Certain costs — permitting, a service call, the inverter, sales overhead — are largely fixed regardless of system size, so they represent a smaller percentage of total cost as the system gets larger, pulling the effective $/W down.