Calculating the True Cost of Running Any Electrical Device

That space heater you run all winter. The gaming PC left on overnight. The pool pump running 12 hours a day. Each of these has a real, calculable monthly cost, and most people have never worked out what it is. The calculation is simple: Watts times Hours divided by 1,000, multiplied by your rate. The insights from applying it to every device in your home are anything but simple. The universal formula Monthly cost = (Watts x Hours per day x 30) / 1000 x Rate You need three numbers: the device wattage (on its label or in its manual), hours of daily use, and your electricity rate (on your bill, measured in dollars per kWh). Example: A 200-watt desktop computer used 10 hours per day at $0.15/kWh. (200 x 10 x 30) / 1000 x $0.15 = $9.00/month That same computer in sleep mode (5 watts) for the remaining 14 hours: (5 x 14 x 30) / 1000 x $0.15 = $0.32/month Total: $9.32/month. Compared to leaving it fully on 24/7: $21.60/month. The devices that cost the most to run I went through every device i