A 2,000 square foot home is the most commonly referenced benchmark for solar panel calculations because it closely matches the median US home size (2,300 sqft) and represents the typical suburban homeowner considering solar for the first time.
The average 2,000 sqft home uses about 900 kWh of electricity per month, or 10,800 kWh per year. To offset this consumption entirely with solar, you need a system that produces 10,800 kWh annually. How many panels that requires depends almost entirely on one variable: how much sun your location receives.
In the sunny Southwest (Phoenix, Las Vegas), 6+ peak sun hours per day means a smaller system of 16 to 18 panels (6.4 to 7.2 kW) covers the full bill. In the cloudy Pacific Northwest (Seattle, Portland), 3.5 peak sun hours require 26 to 30 panels (10.4 to 12 kW) for the same coverage. Most of the US falls between these extremes at 4 to 5 peak sun hours, needing 20 to 24 panels.
This calculator does not ask for your address, zip code, or roof photos. It does not connect you with installers. It estimates your system size based on your electric bill and regional sun exposure, shows the cost before and after the 30 percent federal tax credit, and calculates your break-even timeline. That is the math. What you do with it is your decision.
A typical 2000 sqft home needs 18 to 24 solar panels (7 to 9 kW system), costing $13,000 to $18,000 after the 30% federal tax credit.
The calculation works backward from your electricity consumption. Monthly bill divided by your rate ($/kWh) gives monthly kWh. Multiplied by 12 gives annual kWh. For a $150 monthly bill at $0.14/kWh: 1,071 kWh/month, 12,857 kWh/year.
System size (kW) = annual kWh / (peak sun hours x 365 x 0.80 efficiency). At 4.5 peak sun hours: 12,857 / (4.5 x 365 x 0.80) = 9.8 kW. At 400 watts per panel: 25 panels.
Cost: 9.8 kW x 1000 x $2.75/watt = $26,950 gross. After 30 percent federal tax credit: $18,865 net. Annual savings (assuming full offset): $150 x 12 = $1,800. Break-even: $18,865 / $1,800 = 10.5 years. Panel warranty is typically 25 years, leaving 14.5 years of pure savings after break-even.
Use this calculation when evaluating solar for any home near 2,000 sqft, whether you own it now or are considering buying a home with solar potential. The key input is your electric bill, not your home size. A 2,000 sqft home in Texas with an older AC system might have a $250 monthly bill, while the same size home in Oregon with a heat pump might pay $100. Adjust your bill amount to match your actual utility statements for the most accurate result.