How many watts does a router use?

By Tom Calder · Figures checked 4 November 2026 · Costs at 26.32p per kWh (Ofgem cap, 1 October to 31 December 2026)

In short

A broadband router such as BT’s Smart Hub 2 draws 8.5W to 14W. Because it is on all day, that comes to 0.2 to 0.34 kWh a day: 5p to 9p a day, or £19.60 to £32.47 a year, at 26.32p per kWh.

A kettle coming to the boil beside a microwave and slow cooker in a warmly lit kitchen on a rainy evening

The numbers

Running watts: 8.5W to 14.1W
Amps at 230V (most): 0.06A
Energy a day: 0.2 to 0.34 kWh; 8.5W to 14.1W for 24 hours.
Cost a day: 5p to 9p
Cost a year, left on all day: £19.60 to £32.47
On a 1kWh power station: 32 to 41 hours
On a 2kWh power station: 2.5 to 3.5 days

Costs use 26.32p per kWh, the Ofgem price cap's average Direct Debit electricity unit rate for 1 October to 31 December 2026. Your own rate is on your bill; on a fixed or time-of-use tariff it will differ.

How it’s used, and what that costs

BT publishes the Smart Hub 2 at 14.10W in operation and 8.48W in network standby. Other providers’ hubs vary, and the rating on the power adapter is a worst-case ceiling, not the real draw. Full fibre also needs the Openreach box on the wall, which draws a few watts more.

The honest bit

It is a small draw that never stops: £19.60 to £32.47 a year at 26.32p per kWh.

In a power cut: how long a power station would run it

A 1kWh power station: 32 to 41 hours. A 2kWh power station: 2.5 to 3.5 days. These use the same planning method as our power station pages: capacity × 90% usable depth × 85% inverter efficiency, divided by the load plus about 10W the unit uses itself (BLUETTI’s UK formula).

Output matters as much as capacity. The 7 units around 1kWh we list supply 1,500W to 2,000W continuously, and the 6 around 2kWh supply 2,200W to 3,000W, so check a unit’s rated output covers 14.1W before you rely on it.

On a digital landline, the phone stops working when the router loses power: Ofcom says digital landlines will not work in a power cut, and providers must offer people who rely on their landline a solution, such as a battery back-up, that keeps emergency calls working for at least an hour. Many hubs run from a 12V adapter, and EcoFlow advises using a power station’s DC port to avoid inverter losses, with a lead that matches the hub. See router battery backups.

To size one for everything you’d want to keep running, use the sizer on our power stations comparison.

Common questions

How long will a power station keep my Wi-Fi on?

On our planning method, a 1kWh power station runs a router like BT’s Smart Hub 2 for 32 to 41 hours, and a 2kWh one for 2.5 to 3.5 days, if nothing else is plugged in. A small router battery back-up is cheaper if that is all you need.