EDITORIAL METHODOLOGY

See every assumption behind the result

The calculator uses a focused set of inputs that you can check by hand. Costs it does not include are listed plainly beside the result.

Energy and operating cost

In wattage mode, annual energy equals watts divided by 1,000, multiplied by hours per day, days per week, 365 ÷ 7, and duty cycle. In annual mode, the calculator uses the entered annual kilowatt-hours directly. Annual operating cost equals annual kilowatt-hours multiplied by the electricity rate in dollars per kilowatt-hour.

Comparison and simple payback

Annual savings equal baseline annual cost minus alternative annual cost. Upfront difference equals alternative purchase price minus baseline purchase price. When both values are positive, simple payback equals upfront difference divided by annual savings.

Simple payback is not a complete investment return. A result should be compared with the expected ownership period. If payback exceeds the years a product is likely to remain in service, energy savings alone do not recover the additional purchase cost within that horizon.

Equivalent service comes first

Compare products that do the same job. Capacity, output, operating conditions, and required features can matter more than nameplate watts. If the products do different jobs, the calculator can still show their electricity costs, but it cannot tell you which is the better buy.

How we write decision guides

Decision guides distinguish sourced facts from illustrative assumptions, link to primary sources where practical, disclose material exclusions, and avoid claiming that an average rate is a household tariff. We do not invent product tests, professional credentials, or user outcomes.

For a worked application of these rules, read Keep an old refrigerator or replace it?