Free Home Energy and Eco Label Tools

These tools put numbers behind the choices in our guides. Each one shows its formula, a worked example and the sources and dates behind every figure, runs in your browser, and starts from defaults it names, so you can see and change every assumption.

Size a rooftop system with the solar sizing and payback calculator, which turns your monthly kWh and location into panels needed and, if you enter a quote, a payback estimate using NREL PVWatts yields and EIA electricity rates. Price the smaller upgrades with the home energy savings calculator: LED swaps, standby power and a thermostat setback, in kWh, dollars and CO2. Then check a product’s claims with the eco label decoder, which lists what ENERGY STAR, FSC, GREENGUARD, OEKO-TEX and other labels certify, and what they do not.

For the reasoning behind the tools, read the solar sizing and payback formula, the energy-efficient lighting guide and eco labels explained.