Why 5GHz WiFi dies in the kitchen (and what fixes it)

The living room speed test says 300 Mbps. You walk eight steps to the kitchen counter, open the same app, and it says 40 — then drops out entirely when the microwave goes on. Same router, same phone, same plan. Something about those eight steps is eating almost everything.

It is not a faulty router, and it is probably not your provider. It is the band your phone chose, plus the fact that a kitchen is the single worst room in a Malaysian house for the band it chose.

What 5GHz really trades away

Think of the two bands as two lanes on the same road. 2.4GHz is the wide lane that goes a long way but is shared with the whole neighbourhood. 5GHz is the narrow, empty express lane — much faster when you are on it, but it fades out sooner and it does not like being pushed through anything solid.

Compare it to sound. A bass drum from a neighbour's house gets through your wall; a whistle does not. Higher frequency means more energy lost per metre of wall and per metre of air. 5GHz sits far above 2.4GHz, so it pays that cost on every step you take away from the router — which is why the speed test looks so good in the living room and so bad in the kitchen.

The three-spot test (ten minutes, no app purchase)

Any free WiFi analyser app shows signal strength (RSSI) in dBm. Closer to zero is better: about −50 dBm is excellent, −60 is good, −67 is roughly where video calls start to stutter, and past −75 the connection is alive but useless.

One metre from the router, same room. Note the dBm and the download speed.
The kitchen doorway. Note both again.
The kitchen counter. Same again.

Now read the shape of the drop:

Small at the doorway, large at the counter. Distance is not your problem; the tiles or metal in between is. Move the router.
Already large at the doorway. The problem is direction — a weak side of the router, a concrete column, a water tank in the slab.
Mediocre everywhere. That is a whole-house coverage problem, not a kitchen problem.

What is actually between you and the router

Published attenuation figures vary by material and thickness, so treat these as approximate. The gaps between rows are the real lesson.

What the signal crosses	Typical extra loss	What it means for you
Plasterboard / partition	Small, a few dB	Rarely the villain
Brick wall	Moderate, roughly 6–10 dB	One wall is survivable, two is not
Concrete wall or column	Large, 12–20 dB	Treat concrete as the edge of your coverage
Mirror, metal cabinet, oven door	Very large, often total	Signal reflects or is blocked, not weakened
Tiled wall, wet sink, fridge	Large	Water absorbs 5GHz particularly well
Your own body	Noticeable	Do not stand between phone and router to "test"

A kitchen stacks four of those rows into four square metres: tiles, a fridge, an oven, a sink and running water. That is why the room is famous for killing 5GHz while the bedroom next door is fine.

The cause almost nobody mentions: water

5GHz energy is absorbed by water — the same physics that makes a microwave oven work at 2.4GHz (your router is far too weak to heat anything, so do not worry about that part). In practice it means a sink full of dishes, a kettle, a wet tiled wall, an aquarium or a water tank in the ceiling slab all sit on your signal's path and quietly convert it into nothing useful.

This is also why the drop seems to move around. Signal that is fine at 8am is worse after dinner, because the kitchen is wetter and busier at dinner. Nothing in your router changed — the room did.

Why an extender is often money thrown away

Position. An extender can only repeat what it hears. Plugged into the counter where the signal is one bar, it faithfully rebroadcasts one bar. It belongs in the middle — the kitchen doorway or the corridor outside — where two or three bars still exist.

The halving. A single-radio extender talks to the router and to your phone on the same channel, taking turns, which typically costs around half the throughput it received. You started with a weak-but-fast 5GHz signal and end up with a strong-but-slow one.

So an extender is a waste when it sits in the dead room instead of between the two rooms, when you expected it to make a slow line fast, or when moving the router was free. It is reasonable value when the run between rooms is awkward, when it has a dedicated backhaul radio (most mesh nodes do), or when the alternative is drilling three walls.

The fix order, cheapest first

Move the router higher, out in the open, away from the kitchen wall. Free.
Give the kitchen its own band — most routers let you pin one device to 2.4GHz. A kitchen speaker needs reach, not 5GHz speed.
Change the router's channel if the analyser shows neighbours crowding it. Free, ten minutes.
Add a cabled access point if a cable can reach the corridor ceiling. Full speed on both sides of the wall.
Add a mesh node if no cable is possible — placed at the doorway line, not in the kitchen.
Only then a bigger plan. If the wired test already matches your plan, more bandwidth will not fix a room with four walls in it.

The three-spot test costs nothing and it tells you which of those six you actually need — instead of buying number five for a problem number one would have solved.

Quick answers

Why is my WiFi fast in the living room but slow in the kitchen?

Your phone is almost certainly sitting on the 5GHz band. 5GHz is the fast lane but it loses energy quickly through walls, and a kitchen is the worst room in a house for it: tiled walls, a fridge, an oven door and a sink full of water all absorb or block it. Either move the router, or make the kitchen a place where the 2.4GHz band is easy to pick.

Should I just turn off 5GHz so everything uses 2.4GHz?

That fixes the kitchen and slows everything else down. 2.4GHz reaches further but is crowded and slower, and it is the band your neighbours' routers and your microwave also use. Keep both bands on and let devices choose; only force 2.4GHz on the one device that lives in the kitchen.

Will a WiFi extender fix the kitchen?

Only if you place it where the signal is still decent, which is usually the kitchen doorway, not the kitchen counter. An extender placed in a dead spot repeats a dead spot, and a cheap one also halves the speed because it talks to the router and your phone on the same radio. A cabled access point is better if you can run one cable.

Does a 5GHz signal really get worse with distance and not just walls?

Both. Higher frequencies lose more energy travelling through open air, so a 5GHz signal fades faster than 2.4GHz over the same open distance. Walls and metal make it worse on top of that. That is why the same router can be strong at one end of an open living room and weak two walls away.