About Home Energy Calculators

Last updated June 5, 2026

I read my own electric bill closely enough to get annoyed at black-box “cost to run” tools, so I built ones that show every step: watts, hours, rate, and the dollars that fall out.

What’s on this site

Right now there are 6 calculators here: Appliance Running Cost Calculator, Solar Panel Payback Calculator, Generator Sizing Calculator, LED Savings Calculator, Phantom Load Calculator, and EV vs Gas Cost Calculator. Each one is a single-purpose tool that shows its formula, lists its assumptions, and runs on any device with no signup.

Why these are different

Most calculator sites hand you a number and hide the formula. Every tool here does the opposite: the exact formula, the assumptions, and a worked example are shown right on the page, so you can check the result instead of trusting it blindly. There’s no account, no paywall, and no signup.

How the math is kept honest

Each formula is shown in full and was independently re-derived and spot-checked against the calculator’s code. Reference values (typical rates, averages, rules of thumb) are labeled as approximate and are editable, so you can put in your own real numbers. Estimates here are not financial, tax, or professional energy advice — confirm big decisions (like solar) with a licensed professional.

Found a mistake?

I’d genuinely like to know. Email [email protected] and I’ll fix it.