With energy prices being what they are in the UK, running a gaming PC can feel like feeding a small dragon. So how much electricity does a gaming PC actually use — and what does it cost you per year? The answer varies enormously (a modest build sips power; a flagship rig with an RTX 4090 gulps it), but it’s very calculable. Let’s do the maths.

I’ve measured real gaming PCs with plug-in power meters, and the results consistently surprise people — usually in both directions. Some discover their PC costs less than feared; others realise their “quick evening gaming session” is quietly adding £300+ a year to their energy bill.

How Much Electricity Does a Gaming PC Use? Typical Numbers

Power consumption depends on what the PC is doing — the difference between idle and full gaming load is huge:

The two components that dominate: the graphics card (GPU) accounts for 60–75% of gaming power draw, and the CPU takes most of the rest. Everything else — RAM, SSDs, fans, RGB lighting — is rounding error by comparison. (Yes, even all that RGB. The lighting on a typical gaming PC draws 10–20W total — a fraction of what the GPU uses. Keep your rainbow; it’s not the problem.)

What this means in plain terms

A mid-range gaming PC (e.g. RTX 4060 / RX 7600 class) gaming for 3 hours uses roughly 1 kWh per evening — about the same as running a microwave for an hour, or a kettle boiled 10 times. A high-end rig (RTX 4080/4090 class) can use 2 kWh+ in the same session — comparable to running a tumble dryer for 40 minutes.

What Does That Cost in the UK?

UK electricity is currently around 24–27p per kWh (check your tariff — it varies by region and deal). The maths:

Cost per hour of gaming = PC power draw (kW) × your tariff (p/kWh)

• Mid-range PC (0.35kW gaming): ~9p/hour → 3 hours/day = ~£8/month → ~£95/year
• High-end PC (0.6kW gaming): ~16p/hour → 3 hours/day = ~£14.50/month → ~£175/year
• Flagship PC (0.8kW gaming): ~21p/hour → 4 hours/day = ~£25/month → ~£300/year

And don’t forget idle time: a PC left on 24/7 idling at 80W costs ~£170/year doing absolutely nothing. If your PC sits on all day “just in case”, that’s the easiest saving available — use sleep mode (2–5W) instead.

Measure yours precisely: a plug-in energy monitor (£12–£20) tells you exactly what your PC draws. It’s the only way to know your real number, and it’s oddly addictive watching the wattage jump when a game loads.

How to Reduce Your Gaming PC’s Power Consumption

Without sacrificing the gaming experience:

1. Cap your frame rate

The single biggest lever. If your monitor is 60Hz or 144Hz, rendering 300fps is pure waste — the extra frames are invisible and the GPU works flat-out producing them. Cap frame rates at (or slightly above) your monitor’s refresh rate via in-game settings or the GPU control panel. On a 144Hz monitor, capping a game from 300fps to 144fps can cut GPU power by 30–40% with zero visible difference.

2. Use DLSS / FSR upscaling

NVIDIA DLSS and AMD FSR render the game at lower internal resolution and upscale intelligently. The visual difference is minimal; the power saving is substantial — the GPU does significantly less work per frame. If a game supports it, turn it on (Quality mode is the sweet spot).

3. Undervolt the GPU

Modern GPUs ship with more voltage than they need. A modest undervolt (via MSI Afterburner — free) typically saves 10–20% power with no performance loss. It takes 30 minutes to set up following a YouTube guide, and it’s stable if done conservatively. This is the enthusiast’s favourite trick for a reason.

4. Enable power-saving features

• Windows Power Mode: Settings → System → Power → “Best power efficiency” for desktop use (switch to Best performance only when gaming).
• Monitor sleep: set the display to sleep after 10–15 minutes idle — monitors draw 20–40W.
• Disable “fast startup” wake timers that mysteriously power the PC on overnight.
• Unplug peripherals you don’t use — external drives, USB hubs and old printers sip power constantly.

5. When upgrading, consider efficiency

Newer GPU generations are dramatically more efficient per frame. An RTX 4070 outperforms an RTX 3080 while using ~30% less power. If you’re upgrading anyway, performance-per-watt is worth weighing alongside raw speed — especially with UK energy prices. Our guide to setting up a home office covers the broader desk setup if you’re building out the space too.

Gaming PC vs Console vs Laptop: The Efficiency Comparison

• Gaming laptop: 100–200W gaming — far more efficient, by design (battery constraints force efficiency). A gaming laptop gives maybe 70% of the performance for 30% of the power.
• PS5 / Xbox Series X: ~200W gaming — remarkably efficient for the performance, thanks to fixed hardware and aggressive optimisation.
• Desktop gaming PC: 250–700W — the price of upgradability and maximum performance.

If energy cost is a major concern and you don’t need a PC for work/creation, a console is the rational choice. But for most PC gamers, the optimisation steps above capture the majority of the savings without giving up the platform.

The Bottom Line

A typical UK gaming PC costs £95–£300/year in electricity depending on the hardware and how much you play — meaningful, but rarely the budget-killer people fear. Measure your actual usage, cap your frame rates, enable upscaling, and put the PC to sleep when you’re done. You’ll likely save £50–£100 a year with no noticeable difference to your gaming — money better spent on, well, more games. For context on household energy costs generally, Citizens Advice’s energy guidance is a solid UK resource.

Gaming PC Electricity: Quick FAQs

Does leaving my gaming PC on overnight use much electricity? At idle (~80W), 8 hours overnight costs about 15–18p — roughly £50–£60/year if you do it nightly. Sleep mode (2–5W) costs a fraction of a penny. The habit to break isn’t occasional overnight idling; it’s leaving the PC on 24/7 for weeks.

Do RGB lights use much power? No — a typical full-RGB setup draws 10–20W total. The GPU draws 20–30 times more. Keep the rainbow.

Is it cheaper to game on a console? Per hour, yes — a PS5 or Xbox Series X draws around 200W gaming versus 350–700W for a typical gaming PC. But the PC does far more than game, so compare total household usage, not just gaming hours.

Will undervolting void my warranty? Software undervolting via tools like MSI Afterburner doesn’t modify hardware and doesn’t void warranties. It’s one of the safest tweaks you can make — 10–20% power savings for 30 minutes of setup.

Two more things worth your attention: if your rig sounds like a jet engine, our guide to fixing loud cooling fans covers dust, airflow and thermal paste — the same principles apply to desktop cooling — and protecting your machine from malware matters just as much for a gaming PC as for any other computer.