SolarCalcLab Launches 91 Free Solar and Electrical Calculators Powered by Real Sun Data From PVGIS and NREL
Quick Answer: SolarCalcLab (solarcalclab.com) is a free online platform offering 91 solar and electrical calculators, including system sizing, panel count, battery life, wire size, voltage drop and payback tools. Each calculator uses measured sunlight data for the user’s location and shows the formula and sources behind every result.
PHOENIX, Arizona, November 2, 2026. SolarCalcLab today announced the launch of its full library of 91 free solar and electrical calculators, built to help homeowners, installers, RV and boat owners, and off-grid enthusiasts check the math before they buy. Unlike generic estimators, the platform draws on measured sun data from PVGIS and NREL for the user’s exact location and publishes the equation and sources beneath every result.
Sizing Solar With Real Sunlight, Not Averages
Solar sizing goes wrong when it relies on national averages. A roof in Phoenix receives very different sunlight from one in London or Berlin, and the number of panels needed changes accordingly. SolarCalcLab addresses this by pulling hourly irradiance data for the specific address entered, then applying typical system losses and a transparent formula.
The flagship solar panel calculator lets a user enter a monthly electricity bill or annual consumption and returns a recommended system size in kilowatts peak, the number of panels at a chosen wattage, and the expected output per year with a month-by-month breakdown.
Tools Grouped by the Question People Actually Ask
The library is organized around the questions users bring to it. “How big a solar system do I need?” leads to the solar panel, how-many-panels, panel output, panel angle and peak sun hours calculators. “Will solar pay for itself?” leads to solar cost, payback and ROI, net metering, STC rebate and electricity cost tools. “What battery should I buy?” opens the battery size, battery life, amp hour, backup time and solar generator calculators. “Is my wiring right?” covers voltage drop, wire size, inverter size, MPPT charge controller and string size.
Standards Checked and Sources Named
Every electrical calculator checks limits against the relevant standard, including the NEC in the United States, BS 7671 in the United Kingdom and IEC rules elsewhere, and names that standard on the page. Electricity tariffs are drawn from the US EIA, Ofgem, the Australian AER and Germany’s Destatis, and each tool records when its data was last checked.
“Solar is a large purchase, and most people are handed a quote they have no way to verify,” said a spokesperson for the SolarCalcLab Editorial Team. “We built the site so anyone can see the sun data, the formula and the standard behind a number, and walk into a conversation with an installer already knowing what a sensible system looks like.”
Coverage Beyond the Rooftop
The platform extends well beyond home solar. Off-grid and EV tools cover RV, boat and shed solar systems, EV charging cost, charging time, range and solar EV charging. A home energy section for UK users estimates the running cost of heat pumps, electric showers, immersion heaters, storage heaters, dehumidifiers and tumble dryers. A converter set handles watts to amps, kW to amps, kVA to kW, mAh to Wh and dozens of other everyday electrical conversions.
Policy Context for US Homeowners
SolarCalcLab also tracks how incentives change at the border. For the United States, the site notes that the 30 percent federal residential credit ended on December 31, 2025, which means savings now depend on state net metering rules, state rebates and sales or property tax exemptions. The net metering calculator and accompanying guide help homeowners work through those state-level differences.
Guides That Support the Numbers
Alongside the calculators, the site publishes plain-English guides on topics such as how much power a solar panel produces per day, how many watts a window air conditioner or microwave uses, and how the 2026 solar tax credit landscape works.
Frequently Asked Questions
Are the SolarCalcLab calculators free?
Yes. Every calculator is free to use with no sign-up and no limit on the number of runs. The math runs in the browser, so entered numbers stay on the user’s device.
How accurate are the solar estimates?
The tools use measured sunlight for the location from PVGIS and NREL, typical system losses and the formula shown under each result. Results are planning estimates, and a final design should be confirmed with a licensed installer.
Do the calculators work outside the United States?
Yes. The tools handle US, UK, Australian and German defaults, including AWG and square millimeter wire sizes, 120 V and 230 V mains, local electricity prices and the applicable electrical standards.
Where does the data come from?
Sun data comes from PVGIS and NREL. Electricity prices come from the US EIA, Ofgem, the AER and Destatis. Each calculator names its sources and the date they were last checked.
About SolarCalcLab
SolarCalcLab is a free online platform offering 91 solar and electrical calculators that use real sun data for the user’s location and show the formula and sources behind every result. Results are estimates, and users are encouraged to confirm a final design with a licensed installer. Learn more at https://solarcalclab.com/.
Media Contact
SolarCalcLab Editorial Team
Website: https://solarcalclab.com/
Contact page: https://solarcalclab.com/contact/