How Much Electricity Does a Computer Use — and How to Cut Costs Without Losing Performance

People ask how much electricity a computer uses for all sorts of reasons: an unexpectedly high bill, choosing a UPS or a solar system for a country house, or planning to leave a machine running around the clock. The answer depends heavily on the type of computer and what it's doing: an office mini PC might draw 10–15 watts, while a gaming PC with a powerful graphics card can pull 500–700 watts under load. Let's look at how to work it out and where real savings lie.

Typical consumption of different devices

Note that the wattage printed on the power supply is the maximum it can deliver, not what the computer actually draws. A PC with a 750-watt PSU may use just 70 watts doing office work.

How to calculate the cost

The sum is simple: average power in watts, times hours of use, divided by a thousand, gives kilowatt-hours. For example, an office computer and monitor averaging around 90 watts, used 9 hours a day for 22 days a month: 90 × 9 × 22 / 1000 ≈ 18 kWh a month. A gaming PC averaging 350 watts for 5 hours every day uses about 52 kWh a month. Multiply by your tariff and you have the real figure. The most accurate method is a plug-in power meter, which shows actual consumption.

Where the electricity really goes

Most of the waste usually isn't the work itself but the time a computer sits switched on with nobody using it. A computer left on overnight with programs open and the monitor awake burns electricity for nothing. A gaming PC "just sitting there" with a launcher and browser open can draw 100 watts or more. Hidden miners are a separate story: malware that loads the graphics card around the clock can noticeably raise your bill, and the owner often has no idea.

What genuinely saves energy

• Sleep and shutdown — properly configured sleep after 15–30 minutes of inactivity and monitor power-off save more than anything else.
• Power plans — a balanced plan lets the processor drop its clock speed at idle without hurting responsiveness.
• Frame-rate caps in games — capping FPS at the monitor's refresh rate cuts GPU power draw by tens of percent with no visible loss.
• Undervolting — carefully lowering GPU and CPU voltage reduces power and heat with almost no performance loss. It must be done carefully, with stability testing.
• An efficient power supply — 80 PLUS Gold and better units waste less energy as heat.
• The right hardware for the job — for office work, a mini PC or laptop uses a fraction of what a gaming PC does.
• Dust cleaning — a clogged cooling system makes fans spin faster and components run hotter and less efficiently.

Energy-saving myths

Many people believe switching a computer off for an hour or two is harmful and uneconomical. Modern computers cope with power cycling without trouble, and sleep mode is almost instant while drawing just 1–5 watts. It's also a myth that "an expensive PSU uses more": a high-efficiency unit actually draws less at the same load. And there's no point disabling updates or antivirus to save power — it makes no noticeable difference and creates risks.

Computers and off-grid power

If you're choosing a UPS, inverter or solar system for a home or country house, knowing real consumption is critical, because it determines how long your equipment will run on batteries. A router and a mini PC can run happily on a compact system, while a gaming PC under load would drain it in minutes.

What a technician does

1. Measures the real consumption of the computer and peripherals in different modes.
2. Checks the system for miners and background processes that add unnecessary load.
3. Configures power plans, sleep and monitor shutdown.
4. Carries out safe undervolting with stability testing where appropriate.
5. Cleans the cooling system and checks the power supply.
6. Helps choose a UPS or off-grid system sized for your real load.

A real example

A customer in Isani noticed her electricity bill had risen by almost a third, although nobody at home was spending more time at the computer. We found that her son's gaming PC was never switched off and a hidden miner was holding the graphics card at 90% around the clock. After cleaning the system, setting up sleep and capping frame rates in games, the computer's average consumption fell several-fold and the bill returned to normal.

Peripherals add up too: speakers, printers, chargers and RGB lighting left on standby can draw a few watts each, all day, every day. A switched power strip for the whole desk is a simple fix.

Let us optimise your computer

We work across Tbilisi around the clock, tuning power settings, cleaning systems and removing hidden miners. Learn more on our virus removal, computer setup and computer cleaning pages.