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WiFi Roaming Calculator

Work out the access point spacing and cell overlap that lets devices roam without dropping the connection.

About WiFi Roaming Calculator

Roaming needs adjacent cells to overlap so a client can associate with the next access point before losing the current one. Spacing cells at twice the radius less the overlap fraction gives the layout, and dividing floor area by the effective cell area gives the count. Too little overlap causes dropped calls as users walk between rooms; too much causes co-channel interference and clients that cling to a distant access point.

Formula

WiFi Roaming

Spacing = 2 × cell radius × (1 − overlap); access points = area ÷ effective cell area

cell radius
Distance at which signal still meets the design threshold
overlap
Share of each cell that also sees a neighbouring access point

Worked example

With the default values below, WiFi Roaming Calculator returns Access Point Spacing of 19.20. Change any input above and every figure here is recalculated in your browser.

Inputs used

Usable cell radius per access pointaccepts 1–60 m
12 m
Designed cell overlapaccepts 0–100 %
20 %
Area to coverminimum 10 m2
220 m2
Client roaming thresholdaccepts -85–-55 dBm
-70 dBm

Results

Access Point Spacing
19.20 m
Access Points Required
1
Effective Area per Access Point
289.5 m2
Width of the Overlap Zone
4.80 m
Roaming Advice
Balanced — 15-25% overlap supports seamless roaming

Step by step

  1. 1Values used
  2. 2WiFi Roaming
  3. 3Access Point Spacing= 19.20 m
  4. 4Access Points Required= 1
  5. 5Effective Area per Access Point= 289.5 m2
  6. 6Width of the Overlap Zone= 4.80 m
  7. 7Roaming Advice= Balanced — 15-25% overlap supports seamless roaming

Assumptions and limits

  • The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is WiFi Roaming calculated?

Spacing = 2 × cell radius × (1 − overlap); access points = area ÷ effective cell area Roaming needs adjacent cells to overlap so a client can associate with the next access point before losing the current one. Spacing cells at twice the radius less the overlap fraction gives the layout, and dividing floor area by the effective cell area gives the count.

Why does WiFi Roaming matter?

Too little overlap causes dropped calls as users walk between rooms; too much causes co-channel interference and clients that cling to a distant access point.

What values do I need to enter?

This calculator takes 4 inputs: Usable cell radius per access point, Designed cell overlap, Area to cover, Client roaming threshold. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

Related Calculators

WiFi Roaming Calculator – Calculate Access Point Spacing