Equipment Running Cost Calculator
Add the equipment you run, how many hours a day and how many days a week. We'll show what it costs per day, month and year at the current UK electricity price, the carbon it's responsible for, and whether replacing an old power-hungry device pays for itself.
- Cost per day, month and year
- October 2026 price cap
- Payback on replacements
What it costs
Where the money goes
Each device
| Device | Power | Use | kWh a year | Per day | Per month | Per year | CO2 a year |
|---|
Payback
How we work it out
- Energy: watts × hours ÷ 1,000 = kWh. A 50 W device on for 8 hours uses 0.4 kWh.
- Hours a year: hours a day × days a week × 52.14 weeks. Standby watts count for every other hour of the year's 8,760.
- Cost: kWh × your unit rate. The standing charge is a fixed daily fee you pay whatever you use, so it's left out unless this equipment has its own meter.
- Carbon: kWh × 0.144 kg CO2e, the UK government's 2026 figure for grid electricity (0.131 kg for generation plus 0.013 kg lost in the wires on the way).
- Payback: the new device's price ÷ the money it saves each month.
Prices in October 2026
- The Ofgem price cap from 1 October to 31 December 2026 is 26.32p per kWh and 54.83p a day for electricity on Direct Debit (Great Britain average).
- There's no VAT on household electricity from 1 October 2026 to 31 March 2027, so these figures have none to add. The July to September cap was 26.11p including 5% VAT.
- Your own rate depends on your region, tariff and payment method. Fixed deals and Economy 7 differ: use the figure on your bill.
- Businesses aren't covered by the price cap. The government's latest average for very small business users was 38.36p per kWh (including standing charges, before VAT). Business electricity has 20% VAT unless you use under 33 kWh a day.
Cutting the cost
- Things that run all day and night cost the most: a 10 W router costs about £23 a year, a 150 W old server about £345.
- Let NAS drives sleep when nobody's using them, and turn off monitors, printers and speakers at the wall overnight.
- Replacing an old server that only shares files or runs a small app with a mini PC or NAS often pays for itself in two or three years.
- Planning backup power? The UPS Runtime Calculator uses the same device list, and the Backup Planner sizes the NAS and cloud storage.
Sources
- Ofgem: energy price cap unit rates and standing charges, checked 14 October 2026.
- Department for Energy Security and Net Zero: greenhouse gas reporting conversion factors 2026 and non-domestic electricity prices (table 3.4.2, published 29 September 2026).
- HMRC: VAT on fuel and power.
- Device figures: makers' datasheets (Ubiquiti, Synology, Dell, Sony, Yealink), EU energy labels and SPECpower results, rounded to typical values.