WiFi Extender Placement Calculator

Find how far from the router a WiFi extender should sit so it still receives a strong enough signal to be useful.

About WiFi Extender Placement Calculator

A repeater halves throughput because it receives and retransmits on the same radio, so it must sit where the signal is still strong — around −67 dBm or better. The calculator applies free-space path loss plus a per-wall penalty to test a proposed position. Extenders placed in the dead spot they are meant to fix simply rebroadcast a weak signal; they belong halfway, where the link back to the router is still healthy.

Formula

WiFi Extender Placement

RSSI = transmit power − (free-space path loss + wall loss)

free-space path loss: 20·log10(distance) + 20·log10(frequency) − 28 in metres and MHz
wall loss: About 5 dB per interior wall

Worked example

With the default values below, WiFi Extender Placement Calculator returns Signal at the Extender of -52.6. Change any input above and every figure here is recalculated in your browser.

Inputs used

Router transmit poweraccepts 0–30 dBm: 20 dBm
Proposed extender distance from routeraccepts 1–100 m: 12 m
Band in useaccepts 2–6 GHz: 5 GHz
Walls between router and extenderaccepts 0–8: 1

Results

Signal at the Extender: -52.6 dBm
Link Quality: Excellent — full rate available
Total Path Loss: 72.6 dB
Expected Share of Router Throughput: 50%
Recommendation: Placement works — extender sits inside the reliable zone

Step by step

1Values used
2WiFi Extender Placement
3Signal at the Extender= -52.6 dBm
4Link Quality= Excellent — full rate available
5Total Path Loss= 72.6 dB
6Expected Share of Router Throughput= 50
7Recommendation= Placement works — extender sits inside the reliable zone

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 or fees or charges 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

How is WiFi Extender Placement calculated?

RSSI = transmit power − (free-space path loss + wall loss) A repeater halves throughput because it receives and retransmits on the same radio, so it must sit where the signal is still strong — around −67 dBm or better. The calculator applies free-space path loss plus a per-wall penalty to test a proposed position.

Why does WiFi Extender Placement matter?

Extenders placed in the dead spot they are meant to fix simply rebroadcast a weak signal; they belong halfway, where the link back to the router is still healthy.

What values do I need to enter?

This calculator takes 4 inputs: Router transmit power, Proposed extender distance from router, Band in use, Walls between router and extender. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.