Finding the Right Calculator for Your Question: A Quick Directory

With a large and growing library of tools, here's a quick way to navigate to the right one for whatever question brought you here.

Sizing a solar system

Start with the solar panel calculator for overall sizing, then check roof space, shading impact, and expected production. For a specific usage level, our usage-tier pages offer a fast starting reference.

Understanding cost and financial return

The cost calculator, payback calculator, and ROI calculator cover the core financial questions. For financing specifically, see the loan APR calculator and lease vs buy comparison.

Battery storage and backup power

Start with the battery size calculator, then check duration-specific needs with our outage duration pages or compare against a generator as an alternative.

Electrical basics and appliance costs

For unit conversions, start with watts to amps or the Ohm's Law calculator. For what a specific appliance costs to run, search our library of running-cost calculators — dozens of specific appliances are covered individually, from a general calculator to specific ones for water heaters, dryers, AC units, and more.

EV charging

The general EV charging calculator covers any vehicle; we also have model-specific pages pre-loaded with real specs for dozens of popular EVs, starting from Tesla Model 3.

Your specific location

Check your state's dedicated page for rate, incentive, and net metering details, or your specific city's cost breakdown if we cover it, or your specific utility's rate page for a pre-loaded local rate.

Frequently asked questions