How much does it cost to run a desktop PC in the UK?

Price updated 9 July 2026 · Q3 2026 (Jul–Sep)

A typical desktop PC (250 W) used 4 hours a day, every day costs about £7.94 a month (£95.30 a year) at 26.11p/kWh.

A desktop PC's running cost depends enormously on what it's doing. An office machine browsing and typing might draw 100W, while a gaming PC under load with a powerful graphics card can pull 400–600W. Idle time matters too: a PC left on all day doing nothing still draws power. Sleep and hibernate settings, and simply switching off when finished, are the easiest savings for a machine that isn't a games rig.

Work out your own cost

About £7.94 a month · £95.30 a year

Per hour6.5p
Per day26p
Per week£1.83
Per month£7.94
Per year£95.30

Uses about 365 kWh a year. Prefilled with the Ofgem cap of 26.11p/kWh — edit any box for your own figures.

Cost by model power

The same desktop PC can vary a lot between models, so here is the range from a low-power to a high-power example.

Based on 4 hours a day, every day, at 26.11p/kWh.
ModelPowerPer hourPer dayPer monthPer year
Low-power model 100 W 2.6p 10p £3.18 £38.12
Typical model 250 W 6.5p 26p £7.94 £95.30
High-power model 600 W 16p 63p £19.06 £228.72

What changes the cost

  • Office vs gaming hardware (huge range)
  • Time spent under heavy load vs idle
  • Monitor(s) add their own draw
  • Sleep/hibernate settings
Save money: Enable sleep after a few minutes idle and switch off at the wall overnight — an always-on PC doing nothing is pure waste.

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