The WiFi Network Coverage Radius Calculator estimates a theoretical line-of-sight signal radius from a radio link budget and the free-space path-loss model. It is useful for quick feasibility checks, comparing bands or antenna assumptions, and understanding how transmit power, antenna gain, receiver sensitivity, design margin, and additional environmental loss affect maximum range.
Enter frequency, transmitter power, antenna gains, receiver sensitivity, a fade margin, and any extra loss you want to reserve for walls, foliage, body loss, cabling, or other factors. The calculator converts the remaining path-loss budget into distance. The result is not an indoor site-survey prediction: real WiFi coverage is shaped by building materials, multipath, interference, regulatory transmit limits, client transmit power, antenna patterns, channel width, and required data rate. Treat the distance as a model boundary for the assumptions entered, not a guaranteed service radius.
Inputs
GHz
dBm
dBi
dBi
dBm
dB
dB
Result
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Theoretical WiFi coverage radius
Maximum free-space path loss—
Estimated radius in meters—
Estimated radius in feet—
1. Enter operating frequency Use the center frequency in GHz for the band being evaluated.
2. Enter transmitter power and antenna gains Use dBm for transmit power and dBi for antenna gains. Keep any regulatory or hardware limits in mind.
3. Enter receiver sensitivity Use the sensitivity associated with the minimum data rate or service threshold you actually require.
4. Reserve fade margin Subtract explicit headroom for fading and uncertainty so the design is not based on a zero-margin link.
5. Add environmental loss Use this field to represent walls, foliage, cabling, body loss, or other losses not included in free-space propagation.
6. Review theoretical range The distance is a link-budget estimate and should be validated with RF modeling or a site survey for real deployments.
Maximum path loss (dB) = Tx power + Tx gain + Rx gain − Receiver sensitivity − Fade margin − Extra loss
Free-space path loss (dB) = 92.45 + 20·log10(Frequency GHz) + 20·log10(Distance km)
Distance (km) = 10^((Maximum path loss − 92.45 − 20·log10(Frequency GHz)) ÷ 20)
The model assumes free-space spreading after explicitly subtracting the extra-loss input. It does not model multipath or wall losses by itself.
What the result means
The result is the maximum modeled radius at which received power reaches the selected sensitivity with the entered margins and extra losses.
Real WiFi service range is often lower, especially indoors; validate coverage, capacity, roaming, and uplink performance with deployment-specific RF analysis.
Given: 5 GHz, 20 dBm transmit power, 3 dBi transmit gain, 0 dBi receive gain, −67 dBm receiver sensitivity, 10 dB fade margin, and 12 dB additional loss.
Interpretation: Under this conservative extra-loss and margin assumption, the modeled threshold is reached at roughly 12 meters.
Why can the result be very different from my real indoor WiFi range?
Free-space loss is only one part of RF propagation. Walls, floors, furniture, people, multipath, interference, antenna orientation, and client behavior can all change the usable range substantially.
Which receiver sensitivity should I use?
Use the sensitivity for the minimum modulation rate or service level you want to support, not simply the most sensitive value on a radio specification sheet. Higher required data rates generally need stronger received signal.
What belongs in additional environmental loss?
Use it for losses not already represented by free-space propagation or antenna gain, such as walls, foliage, cable loss, body loss, or a simplified indoor penalty. Avoid double-counting losses already included elsewhere.
Does increasing transmit power always improve coverage?
It increases downlink link budget, but WiFi is bidirectional. Client devices may transmit at lower power, and regulatory limits, interference, and capacity requirements can prevent the downlink range from being the practical service radius.
How is this different from access-point placement planning?
This calculator estimates one theoretical distance threshold. AP placement also requires overlap, roaming, co-channel interference, client density, wall geometry, antenna patterns, and capacity planning across the entire floor plan.