How many access points does an office need? A practical guide

'How many access points does an office need?' The honest answer is 'it depends', but on specific things you can work out: how many people and devices connect, what they do, what the walls are made of and how the space is laid out. With those facts you can make a good first estimate before any survey.

In this guide we explain how we think when designing office Wi-Fi: capacity versus coverage, rules of thumb and their limits, the role of a site survey, channel planning and what changes with Wi-Fi 6 and 7. For whether mesh or wired access points suit you, see our separate comparison guide.

Coverage and capacity: two different questions

Most office Wi-Fi problems are not caused by 'bad signal' but by too many devices on too few access points. An access point can show full bars across the whole floor and still be slow, because it is sharing the same airtime between 60 devices.

• Designing for coverage: does the signal reach everywhere at sufficient strength? Suitable for warehouses and areas with few users.
• Designing for capacity: can everyone work at the same time, with video calls and cloud apps, without lag? This is what almost every office needs.

In practice, the number of access points in an office is almost always set by capacity, not coverage.

Users and devices per access point

Start by counting devices, not people. An employee today usually has a laptop and a phone, often a tablet or a watch too. Add printers, meeting-room screens, phones, smart devices and visitors' devices.

• For office use with email, cloud apps and video calls, a safe target is roughly 20–30 active devices per access point.
• Modern Wi-Fi 6 and 7 access points claim support for hundreds of connections. That is the technical association limit, not the number at which everyone works comfortably.
• Meeting rooms, training rooms and event spaces need their own access point, because they pack many devices into a small area.
• Video calls, voice over Wi-Fi and large file transfers raise the bar. Allow a few Mbps of steady throughput per user for an HD video call, in both directions.

A quick calculation: an office of 25 people with 2 devices each, plus 10 other devices, gives roughly 60 devices. At 25–30 per access point, you need 2 to 3 access points for capacity alone, before you even look at the walls.

Walls, materials and layout

Wi-Fi signal weakens at every obstacle, and more so at 5 and 6 GHz than at 2.4 GHz. In Greek buildings, with concrete, brick and often metal elements, the gap between theory and reality is large.

• Plasterboard and wood: low attenuation. The signal passes one or two partitions easily.
• Glass partitions: plain glass passes easily. Metal-coated or energy-efficient glazing can block a lot.
• Brick: moderate to significant attenuation, especially double walls with render.
• Reinforced concrete (columns, beams, shear walls, slabs): very high attenuation. In practice, each floor needs its own access points.
• Lifts, metal shelving, filing cabinets, fridges, mirrors and aquariums: absorb or reflect the signal and create 'shadows'.

Layout matters too. An open-plan space is far easier to cover than a corridor with ten closed offices on either side. And access points go on the ceiling, near the centre of the areas they serve, not inside cupboards or on shelves.

Square-metre rules of thumb, and their limits

People often ask 'how many square metres does one access point cover?'. To give you a reference point, these are the rules of thumb we use for an initial estimate, always for ceiling-mounted access points:

• Open-plan office with plasterboard: roughly one access point per 80–120 m², depending on desk density.
• Closed offices with brick or concrete: roughly one access point per 50–80 m², often one per two or three rooms.
• Low-occupancy areas such as archives or storerooms: coverage decides here, and one access point can cover a larger area.
• Always at least one access point per floor, and one for every meeting room seating more than 10 people.

These rules are a starting point, not a design. They ignore neighbouring networks, the specific materials, ceiling height and where people actually sit. Use them for an order of magnitude and to check whether a proposal you have received is reasonable.

If someone proposes one powerful access point for the whole office 'because it has long range', ask how many devices it will serve at once. Range solves coverage, not capacity. Also, phones and laptops transmit far more weakly than the access point: they can hear it, but it cannot hear them well.

How many access points does an office need: what the site survey says

The reliable answer to how many access points an office needs comes from a site survey. It is done in up to three stages, depending on the size of the project:

1. Predictive survey: from the floor plan and wall materials, design software predicts coverage and proposes positions. Useful for new spaces, before ceilings are closed.
2. On-site measurement: with a test access point in the proposed position, we measure the real attenuation of the walls. We also record neighbouring networks and interference.
3. Validation survey: after installation, we check that every point meets the targets and fine-tune power and channels.

The targets we use for offices with video calls and voice are a signal of around -65 to -67 dBm or better at every desk, a signal-to-noise ratio (SNR) of at least 25 dB, and every spot able to 'see' a second access point for smooth roaming.

Channel and power planning

More access points do not help if they interfere with each other. Channel planning matters as much as the count.

• 2.4 GHz: only three non-overlapping channels (1, 6 and 11), at 20 MHz width. In a dense office, switch 2.4 GHz off on some access points or keep it only for legacy devices.
• 5 GHz: many more channels. In offices with many access points use 20 or 40 MHz widths, not 80 or 160, so there are enough channels to avoid repeating them side by side.
• DFS channels: add space at 5 GHz, but the access point changes channel if it detects radar. Near airports or ports, their behaviour is worth checking.
• Transmit power: not at maximum. Moderate power makes devices roam when they should and reduces interference.

The automatic settings in platforms such as UniFi and Omada are a good start, but in buildings with many neighbouring networks a manual review after the survey is worth it.

Wi-Fi 6, 6E and 7: does the number change?

Newer Wi-Fi generations do not reduce the number of access points on their own. They do, however, significantly improve how many devices are served together.

• Wi-Fi 6 (802.11ax): OFDMA and MU-MIMO let the access point serve many devices simultaneously. The difference shows in dense spaces.
• Wi-Fi 6E: adds the 6 GHz band, which in Europe is allowed in its lower part (5945–6425 MHz). Clean channels with no legacy devices, but shorter range through walls.
• Wi-Fi 7 (802.11be): adds Multi-Link Operation, using several bands at once, and higher speeds. To make use of it you need a 2.5 Gbps or faster switch port and cabling that supports it.

Because 6 GHz passes through walls less easily, a network designed to make full use of 6 GHz often needs the same number of access points as an older one, or more. The gain is quality, not less equipment.

Indicative examples

To make this concrete, here is how we would start the estimate for three common offices. The final number always comes after the site survey.

• Accounting office, 90 m², 8 people, brick partitions: 2 access points, one on each side of the corridor.
• Open-plan 250 m² with 30 desks and 2 meeting rooms: 3 access points for the open area and 1 for the meeting rooms, 4 in total.
• Two-storey offices, 2 × 150 m², concrete and many closed rooms: 3 access points per floor, 6 in total.

In all three, every access point is wired with Cat6 or Cat6A cable to a PoE switch, and everything is centrally managed, with a separate network for guests.

How we help

CyberSpace Dynamics designs and installs business Wi-Fi for offices across Attica, using equipment such as Ubiquiti UniFi, TP-Link Omada and MikroTik. We measure on site, propose the number and positions of access points, run the cabling, configure channels, power, VLANs and the guest network, and check the result with a validation survey.

If you want to know how many access points your own office needs, send us the floor plan and headcount for a first estimate, or book a free site survey.