☀Solar Panel Cost CalculatorOutput • Savings • Payback • ROI

Free solar panel cost estimator

Solar Panel Cost Calculator

Estimate how much a solar panel system could cost, how much electricity it may generate, how much you could save on bills, and how long it may take to pay back the investment.

Start calculatingSee the formulas
80%Default performance ratio
25 yrsLifetime model
0.5%Default annual degradation

Solar panel cost calculator

Adjust the figures below. Select your currency and enter your local electricity price, export tariff and installation cost.

Self-consumption65%
Annual panel degradation0.5%

Your estimate

Results update instantly from your inputs.

Daily output0 kWh
Monthly output0 kWh
Annual output0 kWh
Panels needed0
Bill savings$0
Export earnings$0
Payback period0 yrs
25-year savings$0
25-year ROI0%

25-year cumulative savings

Net of the installation cost, with yearly panel degradation applied.

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What affects solar panel cost?

Solar panel cost depends on system size, panel wattage, installed price per watt, roof complexity, inverter choice, optional battery storage, permits, grid connection rules and local incentives. This calculator keeps the installed cost editable so it can work across different countries, currencies and tariff structures.

3 kW system
Example installed cost: $4,500-$7,500
Small home or low electricity use.
5 kW system
Example installed cost: $7,500-$12,500
Typical household planning size.
10 kW system
Example installed cost: $15,000-$25,000
Larger home, high usage or more roof space.
Important
These are broad planning examples, not installer quotes. Local prices, incentives and grid rules can change the result significantly.

For a deeper breakdown of project pricing, batteries, roof complexity and quote comparison, read the solar panel cost guide.

How the solar estimate works

The calculator starts with your solar system size and average peak sun hours, then applies a real-world performance ratio. It splits generated energy between self-used solar power and exported solar power.

Annual production = system kW × sun hours × 365 × performance ratio
Panels needed = system kW × 1000 ÷ panel wattage
Annual benefit = self-used kWh × electricity price + exported kWh × feed-in tariff
Payback = installation cost ÷ annual benefit

For more detail on sunlight assumptions, see the peak sun hours guide.

How accurate is this calculator?

This is an educational estimate, not a quotation, financial recommendation or engineering design. Actual solar output and payback can change because of roof direction, roof pitch, shading, local weather, inverter losses, maintenance, export rules, taxes, grants and future electricity prices.

For a better estimate, use your own electricity price, real installer quote, local export tariff and a realistic peak sun hours value for your area.

More solar calculators and guides

Solar panel output calculatorSolar savings calculatorSolar payback calculatorSolar ROI calculatorHow many solar panels do I need?Solar battery calculator5kW solar system output10kW solar system outputSolar panel cost guidePeak sun hours guide
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Solar panel cost calculator FAQ

How much do solar panels cost?

Solar panel cost depends on system size, installed price, roof complexity, inverter choice, optional battery storage, permits, grid rules and incentives. Enter your own installed cost for the most relevant estimate.

How many solar panels do I need?

Divide your target system size in watts by the wattage of each panel. A 5 kW system using 430 W panels needs about 12 panels before roof layout and spacing are considered.

How long does it take solar panels to pay for themselves?

Payback depends on installed cost, electricity price, export tariff, solar production and self-consumption. The calculator estimates payback by dividing installed cost by annual solar benefit.

Is a solar battery worth it?

A battery can increase self-consumption and backup value, but it also adds cost. Compare the additional battery cost against the extra savings from using more of your own solar electricity.

How accurate is this solar panel cost calculator?

It is a planning estimate, not a quote. Actual results vary with roof orientation, shading, weather, tariffs, installer pricing and local regulations.

How much electricity does a 5kW solar system produce?

A 5 kW system with 4.5 peak sun hours and an 80% performance ratio produces about 18 kWh per day before seasonal variation.