โก Electrical
Solar Panel Calculator
The usual mistake when sizing solar is to match the array to annual consumption and forget that winter produces roughly half of summer. Sizing on the annual average leaves you importing power for four months of the year, which is why a small overbuild usually pays for itself.
How it works
Monthly electricity use
Peak sun hours per day
Panel rating
Panel footprint
System losses (wiring, heat, inverter)
Electricity price
Installed cost
Array size
Panels needed
Roof area required
Annual production
Annual bill offset
Share of use covered
Simple payback
COโ avoided per year
Frequently asked questions
How do I use the Solar Panel Calculator?
Fill in the fields above โ the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.