Our Mission
SolarSystemCalc was built around a simple goal: give anyone, anywhere, a fast and reliable way to size a solar power system without needing a spreadsheet, a sales call, or a degree in electrical engineering. Whether you are a homeowner exploring rooftop solar, a student learning how panel tilt affects output, or an installer double-checking a quick estimate, our calculators are designed to be free, instant, and easy to understand.
We built this site because most solar sizing tools online are either locked behind a lead-generation form, tied to a single equipment brand, or too simplified to be genuinely useful. SolarSystemCalc runs entirely in your browser, asks for no personal information, and shows the formulas behind every result so you can see exactly how the numbers were reached.
What Our Tools Do
Our calculators cover the core questions people ask when planning a solar installation: how many panels are needed for a given energy target, how battery storage should be sized, how panel angle and orientation affect output at a given latitude, how much a system might cost and save over time, and how cable and inverter sizing should be approached. Each calculator takes a handful of inputs, applies a documented formula, and returns a result instantly, without page reloads, sign-ups, or waiting.
How We Source Our Data
Where a calculator relies on location-specific solar irradiance, we use publicly available solar atlas and meteorological datasets, compiled into a static dataset that ships with the site rather than queried from a live third-party service. Where a calculator relies on engineering assumptions, such as system losses, inverter efficiency, or wire derating, we use widely accepted rules of thumb from solar industry references. The formula used on every calculator page is shown alongside the result, so you can verify the logic or adapt it to your own project.
Editorial Standards
Every calculator on this site is backed by a documented formula and covered by automated tests that check its output against known reference cases. When we update a dataset or refine a formula, we note the change and the reasoning behind it. Our goal is accuracy and transparency, not persuading you toward a particular product or purchase.
Independence
SolarSystemCalc is an independent online publication. Every calculator is free to use, and the site currently displays no advertising. We do not accept payment to favor one equipment brand or installer over another, and we are not currently affiliated with any solar manufacturer, installer network, or financing company. If that ever changes for a specific page or tool, we will disclose it clearly on that page.
Contact Us
Questions about our methodology, a correction to report, or a partnership inquiry are always welcome at contact@solarsystemcalc.com.