Laptop Electricity Cost Calculator
Enter the laptop's average power draw, how long it runs each day and what you pay for electricity.
How it works
Energy in kilowatt-hours is watts times hours divided by 1,000. A laptop that averages 30 W for 8 hours uses 0.24 kWh a day.
Cost is energy times your price per kWh. The charger's rated wattage is the maximum, not the average: most laptops draw far less than that most of the time.
Questions and answers
Does a laptop use less electricity than a desktop?
Usually much less. Laptop parts are designed for low power, and the screen is built in.
Does leaving the charger plugged in use power?
A modern charger with no laptop attached draws very little, typically a fraction of a watt.
How can I measure my laptop's real draw?
A plug-in energy meter between the charger and the wall shows the actual watts.