The rules of thumb
For a first estimate, size by whichever of these gives the largest number:
- By area: one AP per 100–150 m² of open office, dropping to 60–80 m² in wall-heavy layouts.
- By users: one AP per 20–30 active users (video calls and file-heavy work push toward 20).
- By construction: add an AP whenever coverage must cross more than two solid walls or one floor. Brick, concrete, and glass partitions with metal frames all count as solid.
A 250 m² office with 35 people and standard drywall partitions lands at 2–3 APs. A same-size clinic with masonry walls might need 4–5. The variance is exactly why rules of thumb are a starting point, not a shopping list.
Placement beats count
Three well-placed APs outperform five badly placed ones — and cause less interference. Principles that hold in almost every deployment:
- Ceiling-mount centrally in the areas of densest use, not in the comms cupboard.
- Stagger APs so their strong zones overlap slightly at the edges (about 15–20%).
- Don't put two APs within sight of each other on the same channel; let coverage hand off, not compete.
- Meeting rooms deserve their own consideration — a dozen laptops behind a glass wall is a load and an attenuation problem.
Verify the number with a survey, not a spreadsheet
Here's the measurement-first sizing workflow with a phone-based site survey:
- Import the office floor plan into HeatFi (any blueprint image or a sketch works).
- Survey the current state. Walk the space with the existing router/AP running and generate the heatmap. Every cold area on the map is territory your future APs must cover.
- Test candidate positions. Temporarily move an AP (or even the router) to a proposed spot, re-survey the surrounding rooms, and see the real coverage radius in your building's construction.
- Count the zones. The number of strong-coverage circles needed to tile the plan without cold gaps — that's your AP count, derived from your walls, not a vendor datasheet.
After installation: validate
Re-survey once everything is mounted. Coverage validation is standard practice in enterprise deployments for a reason: furniture, people, and mounting height all shift real-world results. A validation heatmap is also the document you want on file when someone claims "the WiFi is bad" in a room the map shows is fine.
Quick answers
How many access points do I need for a 200 m² office?
Typically 2 APs for open layouts with drywall, 3–4 if there are masonry walls or heavy meeting-room use. Run a walk survey with the floor plan to get the number for your actual construction rather than an average.
Can one access point cover a whole floor?
In open space, one good AP can cover 100–150 m². Add solid walls and the effective radius shrinks fast — the only way to know is to measure signal at the floor's edges with a survey app.
Do more access points mean better WiFi?
Not automatically. Excess APs on overlapping channels create co-channel interference and roaming confusion. Aim for the minimum count that tiles the floor plan with strong coverage, verified by a heatmap.
See your WiFi instead of guessing
HeatFi turns your phone into a WiFi survey tool. Draw your floor plan, walk each room, and get a colour-coded heatmap in minutes. Free — no account needed.
