Disclaimer

Read this before you rely on a number

Last updated November 12, 2026.

These are estimates, not guarantees

Every calculator on this site takes the inputs you give it and runs them through a formula or a lookup table. The output is only as good as those inputs. A panel count, a payback period, a rebate amount: all of it shifts if your actual roof, usage, or local program differs from what you entered.

Site conditions we can't see

No calculator can account for your roof's actual shading pattern, structural condition, local permitting quirks, or the specific equipment an installer plans to use. A real site assessment catches things a web form never will.

Programs change without notice

Rebate amounts, tax credits, and net metering rules are set by state, provincial, and utility programs. These change, sometimes with little public notice. We update figures when we catch a change, but a gap between a program's actual update and our reflecting it here is possible at any time.

Not financial or legal advice

Nothing here is a substitute for advice from a licensed financial advisor, tax professional, or attorney. Financing comparisons in particular depend on your credit, your lender's actual terms, and your specific tax situation, none of which a generic calculator can know.

Always get a real quote

Use these tools to build a baseline before you talk to an installer, not instead of talking to one. A licensed, local installer should confirm your actual system size, cost, and expected output before you sign anything.

Questions

If a specific tool's assumptions are unclear, the contact page is the place to ask.