How to Calculate Appliance Electricity Cost
The formula is simple: monthly cost = (watts ÷ 1,000) × hours per day × 30 days × electricity rate. For example, a 1,500W air conditioner running 8 hours/day at the US average rate of $0.16/kWh costs about $57.60 per month, or $691 per year.
The appliance wattage is printed on a label on the back or bottom of the unit, or in the owner's manual. If you see amps (A) instead of watts, multiply amps × 120V to get watts. Some appliances vary in wattage during operation — a washing machine, for example, draws much more during the heating cycle than during spinning.
The biggest electricity users in a typical US home are central air conditioning, electric water heaters, and electric dryers. Targeting these first gives the best return on energy-saving efforts.
Frequently Asked Questions
Monthly cost = (W ÷ 1,000) × hours/day × 30 × rate ($/kWh). A 1,500W AC at 8h/day at $0.16/kWh = ~$57.60/month.
Check the label on the back/bottom of the appliance or the owner's manual. If it shows amps, multiply by 120V (US standard) to get watts.
Central AC (2,000–5,000W), electric water heaters (4,000–5,500W), electric dryers (4,000–6,000W), and electric ranges (2,000–5,000W) are the biggest consumers.