Wi Fi Coverage Area Calculator

Work out wi fi coverage area instantly with clear inputs, formula shown and shareable results.

About Wi Fi Coverage Area Calculator

Cell radius follows from the link budget — transmit power plus antenna gain minus the target edge signal — applied to a log-distance path loss model where received power falls as 10n log10(distance). The path loss exponent captures the environment: about 2 in open space, 3 in a partitioned office and 4 in industrial space with heavy obstruction.

Formula

Log-distance path loss

EIRP = Tx power + antenna gain; budget = EIRP - target RSSI; radius = 10^((budget - reference loss) / (10n)); area = pi r^2

Worked example

With the default values below, Wi Fi Coverage Area Calculator returns Cell radius of 36.9. Change any input above and every figure here is recalculated in your browser.

Inputs used

Access point transmit poweraccepts -10–30 dBm: 17 dBm
Antenna gainaccepts -10–30 dBi: 3 dBi
Target signal level at the cell edgeaccepts -100–-30 dBm: -67 dBm
Environmentone of Open space (path loss exponent 2.0), Office with partitions (3.0), Dense walls (3.5), Industrial with obstructions (4.0): Office with partitions (3.0)

Results

Cell radius: 36.9 m
Coverage area per access point: 4,271 m2
Effective radiated power: 20.0 dBm
Available link budget: 87.0 dB

Step by step

1Values used
2Log-distance path loss
3Cell radius= 36.9 m
4Coverage area per access point= 4,271 m2
5Effective radiated power= 20.0 dBm
6Available link budget= 87.0 dB

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 1 decimal place, 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

Why does the cell shrink so much indoors?

Because path loss rises with the exponent. Doubling distance costs 6 dB in free space but 12 dB at an exponent of 4, so obstructed environments need many more access points.

Should coverage be designed on the downlink or uplink?

The uplink. Client devices transmit at much lower power than access points, so a cell edge that looks fine on the AP's signal may fail when the client replies.