Planner inputs
Example data table
Use this as a quick template for the nearby networks list.
| SSID | Band | Channel | Width (MHz) | RSSI (dBm) |
|---|---|---|---|---|
| HomeWiFi | 2.4 | 6 | 20 | -48 |
| NeighborA | 2.4 | 1 | 20 | -67 |
| NeighborB | 2.4 | 11 | 20 | -72 |
| CafeWiFi | 5 | 36 | 80 | -61 |
| OfficeMesh | 5 | 149 | 40 | -58 |
Formula used
Each candidate channel gets an interference score by summing overlap contributions from nearby networks:
- Score(channel) = Σ [ SignalWeight(RSSI) × Overlap(channel, width, neighbor) ]
- SignalWeight converts RSSI to a 0–1 weight, emphasizing stronger signals.
- Overlap estimates spectral overlap using channel separation and channel width.
Lower scores mean less expected contention. Multi‑AP planning adds a penalty when AP channels overlap each other.
How to use this calculator
- Scan your area using any WiFi analyzer app.
- Paste networks as CSV lines in the list.
- Select the band and your channel width.
- Set how many access points you will run.
- Press “Plan channels” to see ranked options.
- Apply the top channel on your router settings.
- Export CSV or PDF for documentation.
FAQs
1) Why do channels 1, 6, and 11 matter on 2.4 GHz?
They are spaced far enough to avoid most overlap at 20 MHz width. Using them often reduces contention compared with crowded in‑between channels.
2) Should I use 40 MHz on 2.4 GHz?
Usually no. 2.4 GHz is shared and narrow, so 40 MHz often overlaps multiple neighbors. Use 20 MHz for better coexistence in busy areas.
3) Why does strong RSSI increase the score more?
Stronger nearby signals tend to win airtime and create more contention. The weighting increases their impact so the planner favors channels with fewer strong interferers.
4) Does this replace a real site survey?
No. It’s a planning helper using your scan data. Real performance also depends on walls, device quality, and client density, so validate with speed and latency checks.
5) What about DFS channels on 5 GHz?
DFS channels can be very clean, but radar events may force channel changes. If your devices support DFS well, include those channels in your router’s options.
6) How should I place channels for multiple access points?
Spread channels to reduce overlap between your own APs. This tool suggests a set by penalizing mutual overlap, which helps roaming and reduces self‑interference.
7) What RSSI values should I paste?
Use approximate readings from your scan tool. If you only have signal bars, estimate: strong −45 to −60, medium −61 to −75, weak −76 to −90.