Guides
What home office devices cost to run in the UK
Using Ofgem's 26.32p per kWh cap and manufacturers' published wattages, this guide prices a laptop, monitor and desktop, then shows when an efficient model repays its premium.
What to take away
- Ofgem's price cap for 1 October to 31 December 2026 sets an average electricity unit rate of 26.32p per kWh (Great Britain, direct debit). Electricity carries no VAT from 1 October 2026 to 31 March 2027.
- One watt drawn all year costs about £2.31 at that rate. Multiply any device's watts by its hours to price it.
- Apple's published figures for a laptop idling (3.69 W) and a display in use (30.3 W) show a display drawing about eight times as much as the laptop it is plugged into.
- Hours decide the bill. The same 10 W saving is worth about £5.26 a year on a desk device used 2,000 hours and £23.06 on a device that runs all year.
- Retained UK rules cap notebook off-mode power at 1 W and sleep power at 3 W, so standby is rarely the big cost. Editorial suggestion: hours of use and idle display time matter more.
- Compare devices on total cost over the years you will keep them. Running cost is usually smaller than the price gap between models.
The rate to use, and where it comes from
Your supplier bills each unit of electricity at a rate and adds a daily standing charge. Ofgem's price cap limits both on standard variable tariffs, and Ofgem reviews it every three months. For 1 October to 31 December 2026, the national average for electricity on a direct debit is 26.32p per kWh and 54.83p a day, according to Ofgem's unit rates page. The previous quarter's figure was 26.11p per kWh. Ofgem notes that electricity has no VAT from 1 October 2026 to 31 March 2027, so these figures cannot be compared directly with earlier periods.
Three cautions apply. The cap is an average for England, Scotland and Wales, and Ofgem publishes different unit rates by region and payment method. A fixed tariff may be higher or lower. And the standing charge is payable whether or not you work from home, so it plays no part in choosing a device. Use the rate on your own bill for a real decision. The method below does not change.
Cost in pounds = watts x hours / 1,000 x unit rate in pounds per kWh.
At 26.32p, one watt running for a full year (8,760 hours) uses 8.76 kWh and costs £2.31.
What the devices actually draw
Manufacturer figures are the best primary source for a named model. They are not your real bill. Apple, for example, states that its idle and "on" figures follow the ENERGY STAR test conditions, so video calls, many browser tabs and a bright screen push real use above them. Editorial suggestion: treat the idle figure as a floor.
| Device and mode | Power | Source |
|---|---|---|
| 13-inch MacBook Air (M5), idle, display on, 230 V | 3.69 W | Apple product environmental report |
| Same laptop, sleep / off, 230 V | 0.24 W / 0.11 W | Same report |
| Same laptop's power adapter, no load, 230 V | 0.03 W | Same report |
| Apple Studio Display, on, 230 V | 30.3 W | Apple product environmental report |
| Same display, sleep, 230 V | 0.36 W | Same report |
| Mac mini (M6), idle / maximum | 4 W / 70 W | Apple Support power consumption page |
| Mac mini (M5 Pro), idle / maximum | 6 W / 145 W | Same page |
The pattern matters more than the brand. In Apple's tables, a laptop idles in the low single-digit watts. A display in use draws about eight times as much as that laptop idling. A Mac mini sits near the laptop figure when idle and reaches 70 to 145 W at maximum. These are Apple models, chosen because Apple publishes complete tables. Other makers publish similar sheets, and a model with no published power figure is a reason to ask the seller.
Hours matter more than watts
Take 2,000 hours as a full-time desk year (about 8 hours on 250 days). Multiply by 26.32p per kWh.
| Device and mode | Watts | kWh in 2,000 h | Cost a year |
|---|---|---|---|
| MacBook Air (M5), idle, display on | 3.69 | 7.38 | £1.94 |
| Studio Display, on | 30.3 | 60.6 | £15.95 |
| Mac mini (M6), idle | 4 | 8 | £2.11 |
| Mac mini (M6), maximum | 70 | 140 | £36.85 |
| Mac mini (M5 Pro), idle | 6 | 12 | £3.16 |
| Mac mini (M5 Pro), maximum | 145 | 290 | £76.33 |
Standby costs far less. A laptop asleep at 0.24 W and a display asleep at 0.36 W together draw 0.6 W. Over the 6,760 hours of the year that you are not working, that is 4.06 kWh, or about £1.07. Switching them off at the wall saves roughly that much, and for most desks it is not worth worrying about, apart from tidiness.
Real use sits between idle and maximum. A processor held at its maximum all day is unusual, but a long render, a game or a local build can approach it. If your work does that, the maximum row is the one to use.
The UK rules set ceilings, not typical values. Under Commission Regulation (EU) 617/2013, as retained in UK law, notebook computers' power in off mode may not exceed 1 W and in sleep mode may not exceed 3 W (limits applying from 1 July 2014). The same regulation sets annual energy consumption limits for notebooks of 27, 36 or 60.5 kWh a year depending on the category (from 1 January 2016), before adjustments for extra memory, storage or graphics. At 26.32p those ceilings equal £7.11, £9.48 and £15.92 a year. They show that a compliant laptop's own running cost is small compared with the purchase price.
What the law gives you to check
Several rules affect what you can find out before you buy. The retained texts below are the UK versions on legislation.gov.uk, and the 2021 Regulations extend to England, Wales and Scotland only, so check the position separately in Northern Ireland.
- Computers.Regulation 617/2013 covers desktops, integrated desktops, notebooks (including tablets and slates), thin clients and workstations. It sets the power limits above, plus minimum internal power supply efficiency for desktops: 85% at half load and 82% at 20% and full load.
- Monitors and televisions.The retained Regulation (EU) 2019/2013 sets energy-label and product-information requirements for electronic displays, including televisions, monitors and digital signage displays, with exclusions such as displays of 100 cm² or less, projectors and medical displays. Check the label and information sheet against the model number on the box.
- Repair and updates for displays.The Ecodesign for Energy-Related Products and Energy Information Regulations 2021 add duties for electronic displays. As made, they require manufacturers to keep listed spare parts such as the internal power supply and batteries available to professional repairers for at least seven years after the last unit of the model is placed on the market, to publish the parts list within two years of first sale, and to deliver parts within 15 working days of an order. They require the latest firmware, and its latest security update, to be available for at least eight years after the last unit is placed on the market. Laptops are not among the product groups the 2021 Regulations list, so these duties do not extend to them. See the OPSS and CTSI explainer for how product rules are enforced.
For the buying side of monitors and televisions, see the monitor and television buying guide.
When does an efficient device repay its premium?
Work it out with the rule above. A device that draws 10 W less than another saves:
- 2,000hoursAt a year: 20 kWh, or £5.26 a year, or £31.58 over six years.
- 8,760hoursRunning all year : 87.6 kWh, or £23.06 a year, or £138.34 over six years.
So an efficiency premium of, say, £60 for a monitor that saves 10 W (an assumed figure for the arithmetic) is not recovered by electricity savings if the monitor is used for desk hours. It would be recovered by a device that never switches off. Editorial suggestion: pay extra for efficiency mainly on equipment that runs continuously, and for desk equipment choose on fit, repairability and support, treating power as a tiebreaker.
The same arithmetic shows why a large display matters. In the figures above, the Studio Display's £15.95 a year is eight times the laptop's idle cost. Over six years that is £95.70 for one display, before the purchase price. A monitor that suits your work is still worth buying, but do not treat a bigger screen as free. Editorial suggestion: on a laptop-and-monitor desk, the monitor is the first device to put on a sleep timer.
Total cost of ownership puts everything in one sum: purchase price plus accessories plus running cost plus repairs, minus resale value, divided by years of use. Our technology buying guide shows a worked example with a laptop and dock. The laptop buying guide covers upgrade and repair options, which can extend a laptop's useful life more cheaply than replacement. When you finish with a device, the right to repair and WEEE guide explains the household disposal routes.
Cutting the bill, in order
- Measure before you change anything.Plug an energy monitor or smart plug in between the wall and each device for a normal week. Your own readings beat any table, including this one.
- Set sleep and display timers.Apple's report notes that its laptop's sleep mode starts after 10 minutes of inactivity by default. On Windows, Microsoft documents
powercfg /change monitor-timeout-ac 5, which switches the display off after five minutes on mains power, andpowercfg /energy, which analyses the system for common energy-efficiency problems. - Switch off what you do not use.A switched extension lead for the display, speakers and chargers saves a small amount for no cost. Editorial suggestion: leave the router on, because other people in the house may depend on it.
- Compare total cost before buying.Include accessories, expected life, repair options and resale.
- Check published power and label information.If a maker publishes no power figure, ask.
- Replace on evidence, not on age.A device that meets your workload and can be repaired is usually cheaper to keep. Use the repair diagnosis guide if you are unsure.
