Sources and accountability

Sources, reviews, and corrections

A useful estimate makes its limits visible. Our guides separate documented facts, example inputs, and calculated outputs.

How we use sources

We prioritize U.S. Energy Information Administration data for published electricity averages and government or ENERGY STAR guidance for appliance operation. Source links appear alongside expanded guides. Manufacturer documentation and measured consumption should replace generic planning inputs for your own model.

What a review date means

A guide’s review date identifies its most recent substantive content review. It does not mean a utility tariff was checked that day or an appliance was laboratory-tested. Electricity data has its own period and provenance; averages are not live tariff quotes.

Calculation checks

Our automated checks cover formula examples, input limits, and selected interface behaviors. Tests cannot establish the accuracy of an unmeasured household’s usage. We round displayed currency after calculation and label seasonal, standby, and charging-loss assumptions.

Report a correction

Contact The Developer Guys through their website with the page address, the input values, the result you saw, and the source supporting a correction. Do not send account numbers, exact device coordinates, or an unredacted utility bill. A dedicated in-app reporting channel is not currently available.

Advertising

Reserved advertising areas are labeled separately from calculator results. An ad placement is not evidence that a product is more efficient or suitable for your home.

Read the formulas and exclusions · About Energy Cost Checker