How Much Electricity Does a Desktop Computer Use?
So how much electricity does a desktop computer use? A basic office-style desktop tower draws roughly 120 watts while active and 30 watts or less asleep, and a separate monitor adds another 150 watts active (30 watts or less asleep) on top of that. A gaming desktop with a dedicated graphics card runs considerably higher — use the calculator below with your own system's wattage and rate for a real number.
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What affects how much electricity a desktop computer uses
What's inside the tower matters most: a basic office machine with integrated graphics draws far less than a gaming desktop built around a dedicated graphics card, which can add several hundred watts under load. What you're doing at the moment matters too, since browsing or word processing barely taxes the processor compared to gaming, video rendering, or running several demanding programs at once. Whether the monitor, speakers, and any external drives are counted separately or bundled into your "desktop" figure also changes the total.
How to reduce your desktop's electricity use
- Set the computer and monitor to sleep automatically after a short period of inactivity
- Turn the monitor off (or let it sleep) separately when you're only using the tower for a background task
- Use a power strip to fully cut power to peripherals you're not using rather than leaving them on standby
- Consider a laptop instead if your desktop is mainly used for browsing and documents, since it draws a fraction of the power
Typical wattage figure: roughly 120 W while active (30 W or less asleep) for the tower; add roughly 150 W (30 W or less asleep) if a separate monitor is running. Source: DOE-developed appliance energy table, reproduced by Virginia Cooperative Extension (Virginia Tech), publication BSE-301. A gaming desktop with a high-end graphics card draws considerably more than this reference figure, which represents a basic office-style tower. We review this figure periodically and update it if the source changes; last checked September 2026.
Frequently asked questions
How many watts does a desktop computer use?
A basic office-style desktop tower draws roughly 120 watts while active and 30 watts or less while asleep, according to a DOE-developed appliance energy table reproduced by Virginia Cooperative Extension. A separate monitor adds about 150 watts active (30 watts or less asleep). A gaming desktop with a dedicated graphics card runs considerably higher than this office-machine reference figure.
How much does it cost to run a desktop computer?
A 120-watt tower run 6 hours a day at the U.S. average rate of about 16.5 cents/kWh costs roughly $0.12 a day, or about $3.56 a month, not counting the monitor. Use the calculator above with your own system's wattage (tower plus monitor, if you want a combined figure) and rate for an exact number.
Does a gaming desktop use a lot more electricity than a regular one?
Yes, often substantially more, particularly while actively gaming or rendering. A dedicated graphics card alone can draw several hundred watts under load, on top of the processor and other components, so a gaming rig's peak draw can run several times higher than a basic office desktop's.
How can I reduce how much electricity my desktop computer uses?
Set the computer and monitor to sleep automatically after a short idle period, turn the monitor off separately when you only need the tower running, and use a power strip to fully cut power to peripherals you're not actively using.
This page provides estimates based on typical wattage figures for a basic office-style system and the numbers you enter. A gaming desktop with a dedicated graphics card will draw considerably more, particularly under load; actual electricity cost depends on your specific components and usage pattern.