Solar calculators for every step of your decision
From the first “is solar worth it?” question through financing, system sizing, and battery pairing — 11 free tools that use your state's actual rates and sun hours.
11 free tools, instant results, no signup
Every calculator uses EIA rate data, NREL sun hours, and the current federal ITC schedule. Results update live as you change inputs.
Solar Panel Savings Calculator
Estimate how much you could save with solar panels based on your monthly electricity bill and location.
OpenSolar Installation Cost Estimator
Estimate the gross cost, federal tax credit, and net cost of installing solar panels at your home.
OpenSolar Payback Period Calculator
Calculate how many years it will take for your solar system to pay for itself.
OpenSolar Panel System Size Calculator
Calculate the right solar system size, number of panels, and roof area based on your monthly electricity usage.
OpenSolar Tax Credit Calculator
Calculate the federal Investment Tax Credit (ITC) value for your solar system, including any battery storage.
OpenSolar ROI Calculator
Calculate the 25-year return on investment, net present value, and yearly returns from your solar installation.
OpenSolar Loan vs Cash vs Lease Comparison
Compare the 25-year total cost of paying cash, financing with a loan, or leasing a solar system.
OpenSolar Battery Storage Calculator
Calculate the payback period and value of adding battery storage to your solar system.
OpenSolar + EV Charging Calculator
Calculate how much you save by charging your EV with solar power instead of fueling a gas car.
OpenNet Metering Savings Calculator
Calculate your annual net metering credit value based on monthly solar production and home consumption.
OpenSolar Panel Output by Location
Estimate annual and monthly solar production for your system size based on your state's peak sun hours.
OpenWhy these calculators exist
A quick primer on how the tools fit together and where each one shines.
Our solar calculators help you answer the questions homeowners actually ask before going solar: How much will I save? What size system do I need? When does it pay back? What's the tax credit worth? Is a battery worth adding?
Every calculator works in your browser with no signup, no email capture, and no sales follow-up. We pull rates and incentive data from the EIA, NREL, and IRS / DOE so you can compare scenarios using the same numbers professional installers use.
The calculators here cover the full decision arc — from the headline question ("is solar worth it?") through detailed sizing, financing comparison, and add-ons like batteries and EV charging. Use them in any order. They share consistent assumptions so you can mix-and-match findings to build a complete picture for your home.
Common questions about our solar calculators
How the tools work, which order to use them in, and what the estimates do (and don't) include.