Solar Rooftop Sizing Calculator
Frequently asked
How do I size a rooftop solar system?
Take your monthly electricity consumption in units, divide by 30 to get daily units, then divide by peak sun hours and account for system losses. This calculator does that and matches the system to your roof area.
What system losses should I consider?
Typical losses are 15–25% due to temperature, wiring, inverter efficiency and dust. A 20% loss factor is standard. This calculator lets you adjust it.
How many solar panels do I need for 400 units per month?
For 400 units per month, 5 sun hours and 20% losses, you need about 550W panels producing roughly 6.6 kWh/day. The calculator gives exact panel count based on your inputs.
Which related calculators pair well with the Solar Rooftop Sizing Calculator?
People sizing solar often also need Battery Backup Calculator and Solar Savings Calculator. Each is free and quotation-ready.