Know exactly what solar will cost & save — before a salesperson tells you.
Free, no-signup calculators built on real DSIRE, NREL, EIA and IRS data. Get your true payback period, 25-year savings, loan payment and 2026 incentives in seconds.
Every solar number, one place
No email, no sales call. Each calculator shows its full formula and the real 2026 data behind it.
Solar Payback Calculator
How many years until your panels pay for themselves, with no federal credit for 2026 installs.
Most popular →Solar ROI Calculator
Your 25-year return on investment, total profit, and internal rate of return.
Returns →Solar Loan Calculator
Monthly payment, total interest and break-even on a financed solar system.
Financing →Solar Financing Calculator
Compare cash, loan, lease and PPA side-by-side to find your cheapest path.
Compare →Lease vs Buy Calculator
See the true lifetime cost of leasing versus owning your solar panels.
Decision →Solar Tax Credit Calculator
Check whether a 2025 install still qualifies for the 30% credit, and what changed for 2026.
2025 vs 2026 →Solar Battery Calculator
Size your battery storage and decide whether backup power is worth it.
Storage →Solar Break-Even Calculator
Pinpoint the exact month and year your cumulative savings cross zero.
Break-even →Solar Payback Period Tool
A simple, fast estimate of your payback period with state presets built in.
Quick →Heating & cooling, the efficient way
Heat pumps run at 300–400% efficiency and replace both your furnace and AC. Plan yours with the same honest math.
Heat Pump Cost Calculator
Installed price by home size and type, with 2026 rebates instead of the expired federal credit.
Most popular →Heat Pump Savings Calculator
Yearly savings vs your current gas, oil, propane or electric heat.
Savings →Is a Heat Pump Worth It?
A quick verdict from your system, climate and electricity price.
Decision →Built for homeowners, not installers
Real government data
Every figure traces to DSIRE, NREL, EIA or the IRS — not a sales brochure. We cite our sources on every page.
No email gate, no spam
You won't be asked for your phone number and sold to three installers. Calculate freely, in private.
The full formula, shown
We don't hide the math. Each tool explains its calculation step-by-step so you can check it yourself.
Solar is a different deal in every state
Electricity rates, net metering rules and rebates vary wildly. Pick your state for local payback numbers and incentives.
How to use GreenCalcs
Grab your electric bill
You only need your average monthly bill and your state. That's enough for a solid first estimate.
Pick a calculator
Start with the Payback Calculator, then check ROI, loan payments and your state incentives.
Compare your options
Use the lease-vs-buy and financing tools to find the cheapest way to go solar for you.
Understand the “why” behind the numbers
Plain-English explainers on tax credits, net metering, financing and more — reviewed against IRS, DSIRE and NREL data.
Federal Solar Tax Credit 2026
Why the 30% credit ended and what is left in 2026.
Read guide → RankingsBest States for Going Solar 2026
Why electricity rates and net metering beat sunshine.
Read guide → FinancingLease vs Buy vs Loan
Which way to pay is cheapest over 25 years?
Read guide →