Straight-answer, professional-grade tools that size panels, inverters, batteries and cable in seconds — built on real installation engineering, not a lead-generation funnel.
📲 Install as an app on your phone →Formulas cross-checked against real field engineering practice
Every tool below is free to use, works on mobile, and takes under a minute.
Get panels, battery, inverter and yearly output from one set of inputs — and download a full PDF report.
Find out how many panels you need based on your monthly electricity usage.
Open calculator →Match the right inverter size to your appliances and total system load.
Open calculator →Compare Lithium and Lead-acid capacity requirements for backup hours.
Open calculator →Pick the right cable gauge to avoid voltage drop and overheating.
Open calculator →Estimate your payback period and long-term savings from going solar.
Open calculator →No lead forms, no oversimplified marketing numbers — just the math, explained clearly.
Every calculation is grounded in real installation engineering, not generic textbook averages.
Every tool is free, requires no account, and never sells your contact details to installers.
Enter a few numbers and get a clear, explained result instantly — no downloads, no waiting.
No downloads, no sign-ups — just answers.
Choose the calculator that matches what you're trying to size or estimate.
A few simple inputs — no technical jargon required.
See your answer instantly, plus a short guide explaining how it was calculated.
In-depth explainers that go further than the calculators.
How much panels lose per year and what's left after 25 years — with a real 8-year field measurement.
Read guide → GuideVoc, Vmp, Isc, Pmax, STC and temperature coefficients — explained for real system design.
Read guide →The full explainer behind our panel calculator — formulas, assumptions, and a worked example.
Read guide →Depth of discharge, cycle life, and a full worked example — the guide behind our battery calculator.
Read guide →How payback period and 25-year savings are calculated — the guide behind our ROI calculator.
Read guide →How the three main system types differ, what each costs, and how to decide between them.
Read guide →Degradation rates, what shortens panel life, and what really happens after the 25-year warranty ends.
Read guide →Local sun hours, electricity tariffs, net metering and realistic payback — country by country.
Solar in JordanOne of the sunniest countries on earth, with net metering and fast payback.
Open guide →
Solar in the USAA 30% federal tax credit and net metering in many states — payback varies by state.
Open guide →They give a solid engineering-grade estimate for planning purposes. A professional site survey will fine-tune the number for shading, roof orientation, and system losses specific to your site.
No. Every calculator works instantly in your browser with no sign-up, no email required, and no data sent to a server.
No. SolarToolHub is independent. We don't sell equipment, offer installation services, or pass your details to installers.
Inverter sizing, battery capacity, cable gauge, and ROI/payback period are next, each with a full written guide alongside the tool.