WiFi Frequency Calculator

Wireless networks (802.11) use three unlicensed frequency bands: 2.4 GHz, 5 GHz, and (since 2020) 6 GHz for WiFi 6E. Each band carves its spectrum into numbered channels -- but the numbering systems, channel bandwidths, and regulatory rules differ significantly between bands. The WiFi channel map below the calculator shows every channel's position in the selected band so you can see WiFi channel overlap and congestion at a glance.

The 2.4 GHz band — crowded but universal

14 channels spaced 5 MHz apart from 2412 to 2484 MHz (channel 14 is an outlier at 2484 MHz, Japan-only and 802.11b only). The catch: each WiFi channel actually occupies 22 MHz at 20 MHz mode (or 40 MHz wide). With channels only 5 MHz apart, this means adjacent channels overlap heavily. The classic recommendation in the US/EU is to use channels 1, 6, 11 — the only non-overlapping 20 MHz options. This tool's overlap detector shows which channels conflict with your selection.

The 5 GHz band — more channels, but DFS

5 GHz splits into four sub-bands (the UNII bands):

• UNII-1 (5.15–5.25 GHz): channels 36, 40, 44, 48. Indoor + outdoor, no DFS.
• UNII-2A (5.25–5.35 GHz): channels 52–64. DFS required (Doppler weather radar).
• UNII-2C (5.47–5.725 GHz): channels 100–144. DFS required (military / aviation radar).
• UNII-3 (5.725–5.85 GHz): channels 149–165. No DFS, higher TX power allowed.

DFS (Dynamic Frequency Selection): APs must scan for radar pulses before transmitting on a DFS channel, and immediately vacate the channel if radar is detected during operation. This is why many consumer routers default to UNII-1 or UNII-3 — DFS adds complexity and brief connection interruptions.

The 6 GHz band — WiFi 6E & WiFi 7

5925–7125 MHz, opened for unlicensed WiFi in the US (FCC, April 2020) and many other regions since. Provides 59 channels at 20 MHz, or 29 at 40 MHz, 14 at 80 MHz, 7 at 160 MHz, and (WiFi 7) 3 at 320 MHz. The 6 GHz band has no DFS and far less congestion since it’s brand-new — but requires WiFi 6E or WiFi 7 hardware on both client and AP. Lower TX power for “Low Power Indoor” mode; AFC (Automated Frequency Coordination) lets some outdoor / higher-power use. Because 6 GHz wavelengths are short, an RF wavelength calculator is useful for sizing antenna elements when designing custom access-point enclosures or directional links.

Channel bandwidth tradeoffs

Wider channels (40, 80, 160, 320 MHz) carry more data per Hz of spectrum but consume more spectrum and reach less far. A 160 MHz channel at 5 GHz needs eight 20-MHz channels' worth of clean spectrum — often impossible in dense apartment-building environments. 80 MHz is the sweet spot for modern WiFi 6 in 5 GHz; 160 MHz is where WiFi 6E and 6 GHz shine because the band has so much more clean spectrum. Channel bonding (combining multiple 20-MHz sub-channels) is how 802.11 achieves 40/80/160/320 MHz widths; the “primary” 20-MHz sub-channel carries control frames and beacons while the “extension” channels carry data, which is why the primary channel number is what you configure on the router while the bonded center frequency shifts by half the extra bandwidth.

Co-channel vs adjacent-channel interference

Two networks on the same channel (co-channel interference) actually share airtime politely via CSMA/CA — they can hear each other and back off. Two networks on overlapping but different channels (adjacent-channel interference) are more destructive because they can't hear each other well enough to coordinate, causing corrupted frames and retransmissions. This is why partially overlapping channels in 2.4 GHz are worse than co-channel: if you must share spectrum with a neighbor, matching their channel is usually better than picking one that partially overlaps. Use the overlap detector in this tool to see which 2.4 GHz channels conflict with your selection. The 5 GHz and 6 GHz bands have far more spectrum, so co-channel interference is less common — especially in 6 GHz, where the band is still lightly loaded.