What this tool helps you work out
Wi-Fi coverage is shaped by the building, not just its floor area. Brick, concrete, foil-backed insulation, metalwork, neighbouring networks and the location of the access point can matter more than the router's advertised range.
Coverage details
Wi-Fi Channel Conflict Checker
Estimate channel overlap from nearby 2.4 GHz networks.
Before you begin
Treat any coverage estimate as a survey starting point. The final design should be checked in the real building with the intended access points, channels and client devices.
Use measured values where possible and leave headroom for busy periods, overhead and future growth.
How the result is worked out
The planner combines the area with selected penalties for walls, floors and construction. It estimates how many access points may be needed, but cannot model every reflection, obstruction or source of interference.
Worked example
A two-storey 160 m² home with solid internal walls may need two or three well-placed access points even though one router appears to cover the same area on paper. A wired backhaul usually gives more predictable performance than a distant wireless repeater.
Practical tips
- Place access points in open, central positions rather than cupboards or behind televisions.
- Use wired Ethernet backhaul where practical.
- Use 2.4 GHz for reach and compatibility, and 5 or 6 GHz for higher capacity at shorter range.
- Verify roaming and signal at the places where devices are actually used.
Why one router rarely covers a whole house
Wi-Fi coverage is not a circle drawn around the router. It is a three-dimensional shape distorted by every wall, floor, appliance and water tank in the building, and the router's position in that shape matters more than its specification.
Signal falls with distance even in clear air, and roughly quarters each time the distance doubles. Add the losses from walls and floors and a signal that is excellent in the hall can be marginal two rooms away. This is why the common experience is a house where most rooms are fine and one or two are hopeless — the failure is not gradual, because there is a threshold below which a connection stops being usable rather than merely getting slower.
The other factor is that coverage is a two-way problem. A router with several antennas and plenty of power may reach a distant phone perfectly well, but the phone's reply is transmitted at a fraction of that power from a small antenna. Coverage is limited by whichever direction fails first, and it is usually the device rather than the router.
Most routers sit wherever the broadband socket is, which is typically by the front door, in a hallway, or in a corner of the ground floor — close to an external wall, often low down, sometimes in a cupboard. That position wastes a large share of the coverage outside the building. Moving the router to a central, elevated, open position frequently transforms coverage at no cost, and where the socket makes that impossible, a short Ethernet run to a better position is money well spent.
How many access points, and where
A reasonable planning figure for a typical UK home with brick internal walls is one access point per 70 to 90 m² per floor, with adjustments for construction.
| Home | Construction | Typical requirement |
|---|---|---|
| Flat or small terrace, one floor | Plasterboard partitions | One, centrally placed |
| Two-bed terrace or semi, two floors | Brick internal walls | One well placed, or two if there are dead spots |
| Three or four-bed semi or detached | Brick, concrete floors | Two, one per floor, offset rather than stacked |
| Large or long house, three floors | Solid walls, possible foil insulation | Three or more, ideally wired |
| Anything with a garden office or garage | — | A separate access point out there, wired if at all possible |
Place access points offset from one another rather than directly above, so their coverage overlaps at the edges rather than doubling up in the middle. Aim for enough overlap that a device moving between them never drops below usable, and no more than that.
Wired backhaul, and why it matters more than the hardware
The single largest determinant of whether a multi-access-point setup performs well is how the units talk to each other.
An access point connected by Ethernet has its full radio capacity available for devices. One that connects back over Wi-Fi has to receive every packet and retransmit it, which halves throughput at best, and halves again for each further hop. A three-node wireless mesh can deliver a quarter of the throughput at the furthest node — with excellent signal strength, which is what makes the problem so confusing to diagnose.
- Ethernet is the right answer wherever a cable can be run, including externally in conduit to an outbuilding.
- Existing coaxial or telephone cabling can be pressed into service with the appropriate adapters, and performs far better than wireless backhaul.
- Powerline is unpredictable but often adequate, and depends entirely on the house wiring — same ring main good, different circuits or an old consumer unit poor.
- Dedicated backhaul radio, found on better mesh systems, reserves a radio purely for node-to-node traffic and avoids the halving. It is the reason those systems cost more, and it is a real difference rather than marketing.
- Shared wireless backhaul is the cheapest and the worst, and is what a basic range extender does.
Frequently asked questions
How many access points does a house need?
It depends on layout and construction. A small open home may need one; larger, multi-storey or solid-walled buildings often need more.
Is mesh Wi-Fi the same as wired access points?
Mesh describes coordinated nodes, often with wireless backhaul. Nodes connected by Ethernet usually have more capacity and consistency.
Why is the signal strong but the internet slow?
The access point may have poor backhaul, congested channels, too many clients or a broadband bottleneck.
Should every access point use the same channel?
Usually no. Nearby access points should be planned to reduce co-channel and adjacent-channel interference while still supporting roaming.
Does 2.4 GHz travel further than 5 GHz?
Generally yes through typical buildings, but it also has fewer wide, non-overlapping channel choices and is often more congested.
Is a mesh system better than a single powerful router?
For anything beyond a small flat, generally yes — coverage is a geometry problem, and no amount of power from one point solves it, particularly given that the device's reply is transmitted at low power regardless. Two modest access points sensibly placed beat one expensive one almost every time. The caveat is backhaul: a mesh repeating over wireless gives up a lot of throughput, so wire the nodes together if you possibly can.
Where should I put my router?
Central, high, and out in the open. Away from external walls, metal, mirrors, water tanks and the back of televisions, and not in a cupboard or a media unit. If the broadband socket is somewhere unsuitable, running an Ethernet cable to a better position and putting the router there is usually the highest-value change available.
Do range extenders work?
They extend coverage and reduce throughput, typically by half, because they receive and retransmit everything on the same radio. They also frequently create a separate network that devices hold on to after moving back into the main router's range. They are the cheapest option and the least satisfactory; an access point on a cable costs somewhat more and works properly.
Should I use the same network name for all my access points?
Yes, with the same password and security type, so devices roam between them without manual intervention. Using different names forces you to switch manually and gives no benefit. Modern equipment handles roaming reasonably well under one name; older devices sometimes cling to a weak signal, which is a device limitation rather than a configuration error.
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References
Official guidance and standards can change. Check the linked source when applying the result to an important network.