How this calculation works
Appliance running costs are calculated by multiplying electrical energy consumption in kilowatt-hours (kWh) by your local utility electricity rate.
1. Calculating Kilowatt-Hours
For standard electrical appliances, energy consumption is computed from rated operating wattage, hours of operation per day, days per year, and the device's duty cycle: kWh = (Watts × Hours × Days × Duty Cycle) / 1,000. For devices with standby power (clocks, microcontrollers, transformers), standby energy is added for the remaining hours of the day: (Standby Watts × [24 - Hours] × Days) / 1,000.
For major home appliances like refrigerators and dishwashers, power draws cycle unpredictably throughout the day. For these devices, standardized annual kilowatt-hour ratings from official FTC EnergyGuide labels are used directly.
2. Upgrade Payback
When comparing an existing appliance with a more efficient replacement, annual dollar savings equal (Old Annual kWh - New Annual kWh) × Electricity Rate. The simple payback period represents the replacement purchase price divided by annual savings. Long-term net savings are projected using the shared DoesItPay financial engine, modeling standard 3% electricity rate growth over your chosen equipment horizon.
Data Sources
| Resource | Scope | Source |
|---|---|---|
| Appliance energy use benchmarks | 25+ residential devices | DOE Energy Saver |
| ENERGY STAR appliance ratings | Refrigerators, AC, dryers, bulbs | ENERGY STAR Certified Products |
| Standby & vampire power measurements | Consumer electronics & chargers | Lawrence Berkeley National Laboratory (LBNL) |
| Retail residential electricity rates | New York & US state averages | U.S. Energy Information Administration (EIA) |
Disclaimer: A planning estimate based on your inputs and the assumptions shown. Actual costs and eligibility may differ. Energy consumption varies with usage patterns, ambient temperature, and device efficiency. Not engineering or professional advice.