I’ve always been curious about how much power a WiFi radio consumes. Every time I ask, I get different answers, and everyone seems so confident in their response.
Since I had some free time today, I decided to test it myself and share the results here because why not?

The sample device is a Fiberhome SR1041F, which is arguably the most common, if not one of the most common, router models used in Malaysian households.
Measurement is taken at wall outlet.
To avoid potential power consumption deviations caused by CPU usage from NAT processing under load, the router is operating in bridge mode (aka dumb AP mode).
The single connected client device runs on 802.11ac for 5GHz and 802.11n for 2.4GHz, 5 feet away. The load test consists of a 10GB FTP transfer capped at 500MB server-side, max averaged over three runs.
To keep it short, let's just say the setup and methodology are academically reasonable.





Test is measured over three radio power level in router setting: low ('standard' in fiberhome lingo), medium, and high.
All transfers are conducted over the 5GHz channel. Since I'm not analyzing efficiency, just raw power consumption, I won’t be measuring power usage for activities over 2.4GHz.

Measurement across different radio power
5ghz high, 2.4ghz high
Idle: 4.8w Load: 10.1w

5ghz medium, 2.4ghz medium
Idle: 4.8w Load: 9.7w

5ghz low, 2.4ghz low
Idle: 4.8w Load: 9.2w

What we can say is there in term of power consumption or thermal is, it doesn't matter if your router is idle most of time. There is only about 1w difference in load power consumption between low and high.
But you may still want to lower the power to reduce CCI in mesh situation or congested area.

Idle measurement with one or both radio powered down.
5ghz high, 2.4ghz off
Idle: 4.6w

5ghz off, 2.4ghz high
Idle: 4.4w

5ghz off, 2.4ghz off
Idle: 2.6w


Extra:
Quality of power adapter also have some little effect;
Level V adapter, idle: 5.2w
Level VI adapter, idle: 4.8w

This post has been edited by failed.hashcheck: Mar 13 2025, 05:00 PM