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Both calculators run independently — change the inputs on either side to compare results.

Appliance Energy Cost Calculator

Find the true annual running cost of any appliance from its wattage, hours of use, days per week, your electricity rate, and how many units you run — the load solar has to offset.

Appliance power draw (W)

Hours used per day (h)

Days used per week (days)

Electricity price ($/kWh)

Number of identical units (units)

Solar Energy

Solar Panel System Sizing Calculator

Size a rooftop solar PV system from your real electricity usage, local peak sun hours, system losses, and your target offset — and get the number of panels you actually need.

Average monthly electricity use (kWh)

Peak sun hours (daily average) (h/day)

Share of usage to offset (%)

System losses (inverter, wiring, soiling, heat) (%)

Panel power rating (W)

Key differences

	Appliance Energy Cost Calculator	Solar Panel System Sizing Calculator
Category	Solar Energy	Solar Energy
Inputs required	5	5
Result	Annual running cost ($/yr)	Solar panels needed (panels)
What it does	Find the true annual running cost of any appliance from its wattage, hours of use, days per week, your electricity rate, and how many units you run — the load solar has to offset.	Size a rooftop solar PV system from your real electricity usage, local peak sun hours, system losses, and your target offset — and get the number of panels you actually need.