Professional-use disclosure

Screening outputs, not approvals

Calculator results, reference values, guides, and Workspace reports are provided for informational screening. They are not engineering advice, not a code compliance determination, not a utility bill, not a contractor quote, and not a promise of savings or performance.

Codes and manufacturer instructions come first

Where this site discusses sizing, efficiency, or installation practice, the equipment manufacturer instructions, the locally adopted plumbing and electrical codes, and the authority having jurisdiction always govern. If a calculator result and a code or manufacturer rule disagree, the rule wins. Water heater installation and service work should be performed or supervised by qualified, licensed persons in accordance with local law.

Rates and tariffs must be verified

• Confirm the current energy price: electric cents per kWh or gas dollars per therm, including the fixed customer charge and any seasonal or time-of-use tiers.
• Confirm your usage: twelve months of bills plus your household hot-water gallons per day and cold-water inlet temperature.
• Confirm equipment facts: nameplate input, tank size, first-hour rating, and the UEF rating printed on the label.

No conflicts, no paid placement

Calculator defaults and guide examples are editorial choices, not endorsements. The site does not accept payment to favor equipment, installers, lenders, or rate plans in its tools or content. If that ever changes for a specific page, the relationship will be stated on that page.

Corrections

If a page contains an unclear definition, a broken result, a stale rate, or missing source context, send the URL and the specific issue through Contact. Verified corrections are applied and noted. Contact the site.