Where to put your router, and what is quietly killing the signal

Put the router in the middle of where people actually use wifi, roughly at chest height or above, standing in the open air. Almost every home breaks at least one of those three rules, usually all three at once, because the router ends up wherever the line happens to enter the building. Moving it out of a cupboard and up onto a shelf routinely doubles the usable speed in the far half of a house, at no cost, and it is worth doing before you buy any new hardware. Wifi is a radio signal losing strength the whole way, so the only real question is how much you throw away before it leaves the room.

The three rules that do most of the work

Central. Signal spreads outward in all directions, so a router in a corner sends most of its coverage into the street or next door. Central means central to your living space, not to the floor plan. If everyone sits upstairs in the evening, under the stairs is not central.

High. Off the floor, ideally a meter or more up. Carpet, furniture, appliances and people all absorb signal, and floor level is where they all are. A shelf, a bookcase top or a wall mount all work.

In the open. Not in a cupboard, not behind a television, not inside a media cabinet, not in a metal server rack. Enclosures do two kinds of damage: they attenuate the signal, and they trap heat, and a hot router slows itself down and locks up more often.

If you have more than one floor, aim the router at the middle floor near the stairwell. Wifi passes through an open stairwell far more easily than through a floor slab, which is why one well placed router can cover three levels in one house and fail across two in another.

What actually blocks wifi

Loss is measured in decibels, and the scale is not intuitive: every 3 dB lost is half the signal power, and 10 dB is a drop to one tenth. Two brick walls can therefore cost you more than fifty meters of open air. The figures below are approximate and vary with thickness and construction, but the ranking is reliable.

Two points matter more than the exact numbers. First, the higher the frequency, the worse the loss, so an obstacle that dents 2.4 GHz can end 5 or 6 GHz entirely. That relationship is explained in what the wifi bands trade against each other. Second, angle counts: a signal crossing a wall diagonally passes through much more material than one crossing it square on, so nudging the router a foot sideways sometimes changes a room from unusable to fine.

The hallway cupboard problem

The most common bad placement is the router in a cupboard by the front door, because that is where the line enters. It is a corner, it is at floor level, it is enclosed, and it often has a metal fuse box or a boiler beside it. One spot, all three rules broken. You do not have to accept it. In rough order of how well they work:

1. Run an Ethernet cable from the incoming box to a better spot and put the router there. A long cable along a skirting board is unglamorous and it beats every wireless workaround.
2. Move the incoming socket. Providers often relocate the box that terminates the line during an install, and some will do it later on request. Ask before assuming it is fixed.
3. Use the wiring already in the walls. Adapters that carry a network over existing television coax can deliver hundreds of megabits between rooms, which is a good use of cable sockets you no longer need for television.
4. Mains wiring adapters are the fallback. They work, but speeds vary enormously with your wiring and collapse when the two sockets are on different circuits.
5. Add a wireless node only after the above are ruled out, and place it where it still hears the main router well, not in the dead zone itself. The trade offs are set out in mesh, extender or cable.

If the box your provider supplied cannot be moved, many can be set to pass the connection through to a second router of your choosing, letting the supplied unit stay in the cupboard while the wifi lives somewhere sensible.

Electronics and objects to move away from

Some interference is other people's wifi, which is a channel problem rather than a placement problem and is handled in fixing wifi channel interference. The rest is household hardware sharing the 2.4 GHz band or physically blocking the signal.

• Microwave ovens leak around 2.4 GHz and can flatten that band across a room while running. Keep a couple of meters between the two, and if wifi dies for three minutes at lunchtime every day, you have found it.
• Cordless phone bases and older baby monitors often sit in the same band and transmit constantly.
• Bluetooth speakers and headsets share 2.4 GHz too. They coordinate reasonably well, but a stack of them beside the router does not help.
• Televisions, fridges, radiators, filing cabinets and washing machines are large sheets of metal. Never place a router directly behind or on top of one.
• Set top boxes and consoles add heat when stacked together, and heat is a quiet cause of routers that need weekly restarts.

Antennas, height and the myths

An external antenna is a dipole, and it radiates outward in a doughnut shape around itself, with very little going out of the tip. Vertical antennas therefore cover a floor well and the room directly above poorly. On a router with two or more antennas, keeping one vertical and tilting another to horizontal covers a single floor and the level above it better than pointing them all the same way. Routers with internal antennas assume they will stand upright, so stand them the way the feet suggest.

Three things people believe that are not true. More antennas do not mean more range: extra antennas add parallel data streams, which raises speed for capable devices rather than distance. A foil reflector behind the router redirects a little signal at the cost of everything behind it, which is rarely what you want at home. And raising transmit power, where a router even allows it, does not help much either, because the phone at the far end still has to shout back with its small antenna and limited battery. Coverage is decided by the weaker end of the link.

Survey your house with a phone

Twenty minutes with a phone beats any amount of guessing. Signal strength is reported in dBm as a negative number: about -50 is excellent, -60 is solid, -67 is the usual dividing line for reliable video calls, -70 is marginal and -80 is unusable. On Android, a wifi analyzer app shows this directly. On an iPhone the system restricts that, so use your router's own app or run a quick speed test in each room instead, since throughput is what you care about.

1. Write down every room, plus the garden or garage if you use them.
2. In each one, note the band, the signal reading and a speed test result, standing where you normally sit rather than in the doorway.
3. Move the router to your best candidate spot, wait a minute for devices to reconnect, and repeat the same walk.
4. Compare the two sets. Judge on the worst rooms, not the average, and against what that room needs to do rather than your plan speed, which the speed a household actually needs puts in perspective.

Bars are too coarse to survey with. Three bars can be anything from comfortable to barely working, which is why two rooms that both show full bars can differ by a factor of five in real speed. Measure numbers, not icons, using the method in how to read a speed test.

The twenty minute rearrangement

Do the survey, then move the router as close to the middle of the house as the cable allows, get it a meter off the floor, and take it out of whatever it is hiding in. Retest the two worst rooms. If they improve, buy a longer cable and make the new spot permanent. If they do not, you have learned something useful: the problem is a wall you cannot get around, and a second access point wired back to the router is the honest answer rather than a bigger antenna. And if speeds are poor even standing next to the router, placement was never the issue, so work through the ordered diagnosis for a slow connection and check what your line is delivering before moving furniture again.