Calculators
Free, country-specific tools to estimate your savings, payback, system size and more.
Financial Calculators (13)
- Most Popular
Solar Savings Calculator
Estimate how much a solar system cuts your electricity bill.
22 calculations
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Solar Payback Calculator
How long until your solar investment pays for itself.
9 calculations
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Solar ROI Calculator
Return on investment of going solar over the system's life.
5 calculations
Open Calculator Solar Cost Calculator
Ballpark cost of a solar installation for your home.
2 calculations
Open CalculatorSolar Loan Calculator
Monthly repayments when financing your solar system.
3 calculations
Open CalculatorNet Metering Calculator
Credit you earn exporting surplus units to the grid.
0 calculations
Open CalculatorFeed-in Tariff Calculator
Earnings from a feed-in tariff on exported energy.
3 calculations
Open CalculatorSolar Rebate Calculator
Government rebates and incentives you may qualify for.
1 calculations
Open CalculatorSolar Tax Credit Calculator
See how the federal ITC (30%) and state / utility rebates cut your net solar cost and payback.
1 calculations
Open CalculatorLifetime Savings Calculator
Project your solar savings over its whole life — with tariff inflation, panel degradation, net profit and net present value.
10 calculations
Open CalculatorBattery Storage Payback Calculator
How long a home battery takes to pay for itself by storing cheap solar for use in place of pricier grid power.
0 calculations
Open CalculatorSolar Financing Comparison
Compare paying cash, taking a loan, or leasing (PPA) — side by side over 25 years.
4 calculations
Open CalculatorGenerator vs Solar Calculator
See what your petrol, diesel or gas generator really costs each year — and how fast solar pays for itself by replacing it.
0 calculations
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System Design & Sizing (11)
- Most Popular
Solar System Size Calculator
The system size (kW) your usage actually needs.
6 calculations
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Battery Size Calculator
Battery capacity to cover your backup needs.
2 calculations
Open Calculator Solar Panel Calculator
Panel wattage and configuration for your target output.
0 calculations
Open CalculatorSolar Panel Quantity Calculator
Number of panels needed for your target system size.
0 calculations
Open CalculatorBattery Backup Calculator
How long a battery bank keeps your essentials running.
0 calculations
Open CalculatorInverter Size Calculator
The inverter rating that matches your array and load.
2 calculations
Open CalculatorRooftop Solar Estimator
Find your home on the satellite map, trace your roof, and see the solar system that fits — panels, size, generation and savings.
0 calculations
Open CalculatorSolar Panel Tilt Angle Calculator
The best angle to tilt your panels for your location — year-round, plus summer and winter settings.
0 calculations
Open CalculatorCharge Controller Sizing Calculator
Size the solar charge controller (amps) for your array and battery bank voltage.
0 calculations
Open CalculatorRun Your AC on Solar Calculator
How many solar panels — and what size system — you need to run your air conditioner, plus what it saves off your bill.
0 calculations
Open Calculator
Energy & Performance (7)
Daily Energy Consumption Calculator
Your household's daily energy use in kWh.
4 calculations
Open CalculatorAppliance Load Calculator
Combined load of the appliances you want on solar.
0 calculations
Open CalculatorSolar Generation Calculator
Energy your system generates from local sun hours.
0 calculations
Open CalculatorMonthly Solar Output Calculator
Month-by-month output expected from your system.
0 calculations
Open CalculatorSelf-Consumption Calculator
How much of your solar you use yourself versus export to the grid — and how a battery lifts it.
0 calculations
Open CalculatorPanel Degradation Calculator
Estimate how your panels' output fades year on year, and the total energy they deliver over their life.
0 calculations
Open CalculatorBattery Charge Time Calculator
How long it takes to charge your battery from a given solar or charger power.
0 calculations
Open Calculator
Environmental Impact (2)
Electric Vehicle (EV) (1)
EV Charging Cost Calculator
Cost of charging your EV from the grid vs solar.
24 calculations
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Engineering Tools (4)
Solar Cable Size Calculator
The minimum DC cable size to keep voltage drop within your target over the run length.
0 calculations
Open CalculatorPanel Temperature Derating Calculator
How much power your panels lose to heat above their 25°C rated conditions.
0 calculations
Open CalculatorString Sizing Calculator
Panels per string within inverter voltage limits.
3 calculations
Open Calculator
Product & Buying Tools (1)
Solar Product Comparison Calculator
Compare panels and inverters side by side on specs.
1 calculations
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Your Calculations, Your Insights
Track your calculation history, compare results, and make better solar decisions.