Most homes need 300-600 square feet of solar panel area. This typically means 15-25 panels depending on efficiency. Check your electric bill for kWh consumption and use our calculator above. Can I install solar panels in a small space?The total area needed for solar panel installation is vital for effective PV system design and planning. Whether you want to power your whole house or just reduce bills, knowing your solar panel area. A typical home solar panel is about 3 feet wide by 5. This calculator provides estimates only and should not be used as the sole basis for solar system purchases or financial. Online solar calculators can give a rough estimate of how much solar you need to power your home, but you may want to perform your own sizing calculations to fine-tune your choices. Here's a step-by-step overview of the process we follow when sizing solar systems for our customers. Note: This. An off-grid solar system's size depends on factors such as your daily energy consumption, local sunlight availability, chosen equipment, the appliances that you're trying to run, and system configuration.