Free Solar & Heat Pump Calculators
Every GreenCalcs tool in one place — 15 free calculators for solar payback, ROI, financing, tax credits, batteries, and heat pump cost, sizing and savings. No sign-up, no email, and every tool shows its full formula on the page.
Solar calculators
Solar Payback Calculator
How long until your panels pay for themselves.
Open calculator →Solar ROI Calculator
Your 25-year return and lifetime profit.
Open calculator →Solar Loan Calculator
Monthly payment and total cost of a solar loan.
Open calculator →Solar Financing Calculator
Compare cash, loan and financing options.
Open calculator →Lease vs Buy Calculator
Owning vs leasing over the system's life.
Open calculator →Tax Credit Calculator
Your exact 30% federal credit.
Open calculator →Solar Battery Calculator
Whether storage pays off for you.
Open calculator →Break-Even Calculator
The year your solar turns net-positive.
Open calculator →Payback Period Calculator
A quick payback estimate in years.
Open calculator →Heat pump calculators
Heat Pump Cost Calculator
Installed cost after the federal credit.
Open calculator →Heat Pump Size Calculator
The right capacity (BTU/tons) for your home.
Open calculator →Heat Pump Capacity Calculator
Match capacity to your heat load.
Open calculator →Heat Pump Savings Calculator
Annual savings vs your current heating.
Open calculator →Geothermal Calculator
Ground-source cost and the uncapped credit.
Open calculator →Is a Heat Pump Worth It?
A quick verdict for your home.
Open calculator →