An appliance cost estimate turns power into energy and energy into money. The most important judgment is usually realistic runtime, especially for thermostatically controlled equipment.
Convert watts to kWh
Daily energy = watts × hours per day ÷ 1,000. A 1,500 W appliance running for 3 hours uses 4.5 kWh. At $0.16 per kWh, that is $0.72 per day.
Scale to a month or year
Multiply the daily cost by 30 for a planning month or 365 for a planning year. A real billing cycle may differ, so label the assumption rather than presenting it as an invoice forecast.
Account for cycling
A heater may run only 40 minutes per hour, and an air conditioner’s compressor may cycle. Replace full-power runtime with a measured or estimated duty cycle when accuracy matters.
Compare alternatives
Use the same rate, time horizon, and comfort/output assumption when comparing appliances. A cheaper hourly estimate may deliver less heat, cooling, or work, so cost alone is not the full decision.
Sources
The figures and rules in this guide are checked against:
- Electricity Explained: Measuring Electricity — U.S. Energy Information Administration
- Electricity Explained: Use of Electricity — U.S. Energy Information Administration
- Residential Energy Consumption Survey (RECS) — U.S. Energy Information Administration
- ENERGY STAR Product Finder — U.S. EPA ENERGY STAR