Solar Panel Roof Space Calculator

A correctly sized solar system is the difference between a great investment and a disappointment. This Solar Panel Roof Space Calculator sizes your off-grid or hybrid solar system from your daily energy needs and the peak sun hours in your city, telling you the kW system and battery capacity required.

The calculation works backwards from what you actually consume: your daily kilowatt-hours divided by the usable sun hours gives the solar array size, and your night-time load determines the battery bank. Oversizing wastes money; undersizing leaves you on the grid — this tool finds the balance.

Peak sun hours vary across Pakistan — Quetta and the south see more than the northern cities. The calculator's sun-hours input lets you set the figure for your location, or use the default for a typical Pakistani city.

Beyond the array size, factor in losses: inverters, wiring and battery efficiency typically mean you should add a 20–25% margin to the theoretical size. The results here give you the honest engineering figure to discuss with installers, so you can compare quotes on an equal basis.