How much does a desktop PC cost to run?

Figures on this page are calculated from typical appliance wattages and the price per kWh you enter, not looked up from a bill. See how we calculate this.

What a desktop PC costs to run: typical 200 W, about $33 a year. Adjust the figures to your own usage and electricity price.

Wattage and running cost

Based on 2.5 h a day at $0.18/kWh, the US average. Change the hours and the price in the calculator above.

A desktop PC uses far more electricity than a laptop doing the same tasks, because it is built for performance rather than battery life. A basic office desktop might draw 80 to 150 watts, a typical machine around 200 watts, and a powerful gaming or workstation PC 400 to 600 watts or more under load — before you add the monitor. This page uses an hours-per-day approach; enter a realistic figure for how your machine is actually used, since the draw swings widely between idle browsing and heavy gaming or rendering.

The key detail is that power varies enormously with the workload. The same PC that sips 90 watts while you write emails can pull five times that while gaming, so the honest yearly cost depends on how you use it, not just how long it is on. Leaving a desktop running around the clock — a common habit — is where the real waste hides, because even at idle it draws far more than a sleeping laptop. Sleep and hibernate settings, and pairing it with an efficient monitor, are where the savings are.

If your machine is a gaming or workstation build, the graphics card is usually the biggest single draw, spiking only under heavy load. For everyday tasks it idles far lower, so the yearly cost is really a story of two numbers: a modest idle figure most of the time, and short, expensive bursts when you genuinely push it hard.

For context, a typical laptop doing the same office tasks draws roughly 30-65 W — a fraction of even a modest desktop's 150-200 W. Over a year of daily use, that gap alone is often worth real money at typical prices, before counting the desktop's separate monitor. That is not a reason to avoid desktops — performance per watt for demanding work still favours them — but it is worth knowing the running-cost premium you pay for a machine that is always the more powerful option.

The single number that decides a desktop's running cost is the graphics card, and it only matters when the machine is actually working. An office PC with integrated graphics idles at 50 to 80 W and rarely leaves that range; the same box with a mid-range GPU sits at a similar idle but climbs to 300 W or more the moment a game or a render starts. That is why the power supply rating on the side of the case is no help at all — an 850 W unit does not draw 850 W, it is a ceiling. What you pay for is the average over the hours the machine is on, which for most people is much closer to idle than to peak.

What a desktop PC costs in other countries

The figures above assume $0.18/kWh, the US average. A desktop PC does not change when it crosses a border — the price of the electricity it drinks does. Here is what its 183 kWh a year cost in the 14 countries with a page here, dearest first.

Each figure is in that country's own currency at its average all-taxes-included price; the dollar column is there so they can be set against each other. Ireland to Canada is a factor of 3.8 — same appliance, same hours, 3.8 times the bill. Follow a country for its real retailer tariffs and what makes up that price, or see the full electricity price comparison by country.

How to cut desktop PC running costs

• Set the PC to sleep or hibernate when idle instead of leaving it running.
• Don't leave it on overnight for downloads unless you really need to.
• Enable power-saving modes; they cut idle draw with no real downside for office work.
• A laptop does everyday tasks for a fraction of a desktop's power — consider it for light use.
• Undervolting or an efficient power supply helps on high-end gaming machines.

Frequently asked questions