Ever wonder what the space heater, gaming PC, or old fridge actually costs? Enter watts, daily hours, and the electricity rate for daily, monthly, and yearly figures.
Energy use in kilowatt-hours is watts × hours ÷ 1000. Multiply by the rate on the electricity bill (the US average residential rate is roughly 16 cents per kWh, but it ranges from about 10 to over 35 cents by state). The appliance label or a plug-in power meter gives the watts; for devices with a range, use the typical draw, not the maximum.
Where do I find the watts? On the label near the power cord, in the manual, or on the power brick. If only amps and volts are shown, watts = amps × volts.
What rate should I use? The per-kWh price on your bill, ideally including delivery charges — divide the total bill by kWh used for the true all-in rate.