A laptop computer typically uses 20 to 75 watts, depending on its size, make and model. The actual wattage should be listed on the laptop or instrument panel.
A laptop costs about $8 per year to run at roughly 72 kWh according to Forbes Magazine. In comparison to other devices used in households, this cost and wattage is fairly low. For example, as of 2014, the average laptop draws 20 to 75 watts, while a coffee maker uses 600 to 1200 watts to run. If a Keurig coffee machine remains plugged in, it requires 200 to 400 continuous watts, and a maximum of 1,500 watts. A laser printer requires much more wattage, with roughly 2,000 watts at its peak.
To estimate how many watts are continuously running at the same time, use the total wattage multiplied by 20 percent, which is a minimum power requirement. Other common appliances that require a fair amount of wattage include a hair dryer, which is estimated at 1,000 to 1,875 watts, and a toaster oven, which requires 1,200 watts. Low-wattage appliances include a cellphone charger at 10 watts, a clock radio estimated at 10 to 50 watts and a inkjet printer estimated at 15 to 75 watts.